Dynamic PRACH scheduling using slot formats

ABSTRACT

A wireless device receives a radio resource control message from a base station. The radio resource control message comprises one or more configuration parameters for a random access channel. A downlink control information is received that comprises a field indicating a slot format indication, for a slot, among a plurality of SFIs. The plurality of SFIs indicate uplink, flexible, and random access symbols. The wireless device determines radio resources of one or more random access channel occasions of the slot based on the one or more configuration parameters and at least one random access symbol indicated by the slot format indication for the slot. A preamble is transmitted via the radio resources of the one or more random access channel occasions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/805,908, filed Feb. 14, 2019, which is hereby incorporated byreference in its entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1 is a diagram of an example RAN architecture as per an aspect ofan embodiment of the present disclosure.

FIG. 2A is a diagram of an example user plane protocol stack as per anaspect of an embodiment of the present disclosure.

FIG. 2B is a diagram of an example control plane protocol stack as peran aspect of an embodiment of the present disclosure.

FIG. 3 is a diagram of an example wireless device and two base stationsas per an aspect of an embodiment of the present disclosure.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure.

FIG. 5A is a diagram of an example uplink channel mapping and exampleuplink physical signals as per an aspect of an embodiment of the presentdisclosure.

FIG. 5B is a diagram of an example downlink channel mapping and exampledownlink physical signals as per an aspect of an embodiment of thepresent disclosure.

FIG. 6 is a diagram depicting an example frame structure as per anaspect of an embodiment of the present disclosure.

FIG. 7A and FIG. 7B are diagrams depicting example sets of OFDMsubcarriers as per an aspect of an embodiment of the present disclosure.

FIG. 8 is a diagram depicting example OFDM radio resources as per anaspect of an embodiment of the present disclosure.

FIG. 9A is a diagram depicting an example CSI-RS and/or SS blocktransmission in a multi-beam system.

FIG. 9B is a diagram depicting an example downlink beam managementprocedure as per an aspect of an embodiment of the present disclosure.

FIG. 10 is an example diagram of configured BWPs as per an aspect of anembodiment of the present disclosure.

FIG. 11A, and FIG. 11B are diagrams of an example multi connectivity asper an aspect of an embodiment of the present disclosure.

FIG. 12 is a diagram of an example random access procedure as per anaspect of an embodiment of the present disclosure.

FIG. 13 is a structure of example MAC entities as per an aspect of anembodiment of the present disclosure.

FIG. 14 is a diagram of an example RAN architecture as per an aspect ofan embodiment of the present disclosure.

FIG. 15 is a diagram of example RRC states as per an aspect of anembodiment of the present disclosure.

FIG. 16A, FIG. 16B, and FIG. 16C are diagrams of example slot formats asper an aspect of an embodiment of the present disclosure.

FIG. 17 is a diagram of example slot format mapping as per an aspect ofan embodiment of the present disclosure.

FIG. 18A, and FIG. 18B are diagrams of example slot format combinationsas per an aspect of an embodiment of the present disclosure.

FIG. 19 is a diagram of example COT structure as per an aspect of anembodiment of the present disclosure.

FIG. 20 is a diagram of example signaling for dynamic PRACH schedulingas per an aspect of an embodiment of the present disclosure.

FIG. 21 is a diagram of example signaling for dynamic PRACH resourceallocation resulting in preamble transmission as per an aspect of anembodiment of the present disclosure.

FIG. 22 is a diagram of example slot format configuration indicatingrandom access symbols as per an aspect of an embodiment of the presentdisclosure.

FIG. 23 is a diagram of example dynamic PRACH resource scheduling usingslot formats as per an aspect of an embodiment of the presentdisclosure.

FIG. 24 is a diagram of example signaling for dynamic PRACH resourceallocation resulting in cancellation of DL transmission per an aspect ofan embodiment of the present disclosure.

FIG. 25 is a diagram of example signaling for dynamic PRACH resourceallocation resulting in cancellation of UL transmission per an aspect ofan embodiment of the present disclosure.

FIG. 26 is a flow diagram of an example embodiment for a wireless devicescheduled with dynamic PRACH using slot formats as per an aspect of thepresent disclosure.

FIG. 27 is a flow diagram of an example embodiment for a base stationdynamically scheduling PRACH using slot formats as per an aspect of thepresent disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present disclosure enable operation of randomaccess. Embodiments of the technology disclosed herein may be employedin the technical field of multicarrier communication systems. Moreparticularly, the embodiments of the technology disclosed herein mayrelate to dynamic scheduling of random access resources in amulticarrier communication system.

The following Acronyms are used throughout the present disclosure:

-   -   3GPP 3rd Generation Partnership Project    -   5GC 5G Core Network    -   ACK Acknowledgement    -   AMF Access and Mobility Management Function    -   ARQ Automatic Repeat Request    -   AS Access Stratum    -   ASIC Application-Specific Integrated Circuit    -   BA Bandwidth Adaptation    -   BCCH Broadcast Control Channel    -   BCH Broadcast Channel    -   BPSK Binary Phase Shift Keying    -   BWP Bandwidth Part    -   CA Carrier Aggregation    -   CC Component Carrier    -   CCCH Common Control CHannel    -   CDMA Code Division Multiple Access    -   CN Core Network    -   CP Cyclic Prefix    -   CP-OFDM Cyclic Prefix-Orthogonal Frequency Division Multiplex    -   C-RNTI Cell-Radio Network Temporary Identifier    -   CS Configured Scheduling    -   CSI Channel State Information    -   CSI-RS Channel State Information-Reference Signal    -   CQI Channel Quality Indicator    -   CSS Common Search Space    -   CU Central Unit    -   DC Dual Connectivity    -   DCCH Dedicated Control CHannel    -   DCI Downlink Control Information    -   DL Downlink    -   DL-SCH Downlink Shared CHannel    -   DM-RS DeModulation Reference Signal    -   DRB Data Radio Bearer    -   DRX Discontinuous Reception    -   DTCH Dedicated Traffic CHannel    -   DU Distributed Unit    -   EPC Evolved Packet Core    -   E-UTRA Evolved UMTS Terrestrial Radio Access    -   E-UTRAN Evolved-Universal Terrestrial Radio Access Network    -   FDD Frequency Division Duplex    -   FPGA Field Programmable Gate Arrays    -   F1-C F1-Control plane    -   F1-U F1-User plane    -   gNB next generation Node B    -   HARQ Hybrid Automatic Repeat reQuest    -   HDL Hardware Description Languages    -   IE Information Element    -   IP Internet Protocol    -   LCID Logical Channel IDentifier    -   LTE Long Term Evolution    -   MAC Media Access Control    -   MCG Master Cell Group    -   MCS Modulation and Coding Scheme    -   MeNB Master evolved Node B    -   MIB Master Information Block    -   MME Mobility Management Entity    -   MN Master Node    -   NACK Negative Acknowledgement    -   NAS Non-Access Stratum    -   NG CP Next Generation Control Plane    -   NGC Next Generation Core    -   NG-C NG-Control plane    -   ng-eNB next generation evolved Node B    -   NG-U NG-User plane    -   NR New Radio    -   NR MAC New Radio MAC    -   NR PDCP New Radio PDCP    -   NR PHY New Radio PHYsical    -   NR RLC New Radio RLC    -   NR RRC New Radio RRC    -   NSSAI Network Slice Selection Assistance Information    -   O&M Operation and Maintenance    -   OFDM Orthogonal Frequency Division Multiplexing    -   PBCH Physical Broadcast CHannel    -   PCC Primary Component Carrier    -   PCCH Paging Control CHannel    -   PCell Primary Cell    -   PCH Paging CHannel    -   PDCCH Physical Downlink Control CHannel    -   PDCP Packet Data Convergence Protocol    -   PDSCH Physical Downlink Shared CHannel    -   PDU Protocol Data Unit    -   PHICH Physical HARQ Indicator CHannel    -   PHY PHYsical    -   PLMN Public Land Mobile Network    -   PMI Precoding Matrix Indicator    -   PRACH Physical Random Access CHannel    -   PRB Physical Resource Block    -   PSCell Primary Secondary Cell    -   PSS Primary Synchronization Signal    -   pTAG primary Timing Advance Group    -   PT-RS Phase Tracking Reference Signal    -   PUCCH Physical Uplink Control CHannel    -   PUSCH Physical Uplink Shared CHannel    -   QAM Quadrature Amplitude Modulation    -   QFI Quality of Service Indicator    -   QoS Quality of Service    -   QPSK Quadrature Phase Shift Keying    -   RA Random Access    -   RACH Random Access CHannel    -   RAN Radio Access Network    -   RAT Radio Access Technology    -   RA-RNTI Random Access-Radio Network Temporary Identifier    -   RB Resource Blocks    -   RBG Resource Block Groups    -   RI Rank Indicator    -   RLC Radio Link Control    -   RRC Radio Resource Control    -   RS Reference Signal    -   RSRP Reference Signal Received Power    -   SCC Secondary Component Carrier    -   SCell Secondary Cell    -   SCG Secondary Cell Group    -   SC-FDMA Single Carrier-Frequency Division Multiple Access    -   SDAP Service Data Adaptation Protocol    -   SDU Service Data Unit    -   SeNB Secondary evolved Node B    -   SFN System Frame Number    -   S-GW Serving GateWay    -   SI System Information    -   SIB System Information Block    -   SMF Session Management Function    -   SN Secondary Node    -   SpCell Special Cell    -   SRB Signaling Radio Bearer    -   SRS Sounding Reference Signal    -   SS Synchronization Signal    -   SSS Secondary Synchronization Signal    -   sTAG secondary Timing Advance Group    -   TA Timing Advance    -   TAG Timing Advance Group    -   TAI Tracking Area Identifier    -   TAT Time Alignment Timer    -   TB Transport Block    -   TC-RNTI Temporary Cell-Radio Network Temporary Identifier    -   TDD Time Division Duplex    -   TDMA Time Division Multiple Access    -   TTI Transmission Time Interval    -   UCI Uplink Control Information    -   UE User Equipment    -   UL Uplink    -   UL-SCH Uplink Shared CHannel    -   UPF User Plane Function    -   UPGW User Plane Gateway    -   VHDL VHSIC Hardware Description Language    -   Xn-C Xn-Control plane    -   Xn-U Xn-User plane

Example embodiments of the disclosure may be implemented using variousphysical layer modulation and transmission mechanisms. Exampletransmission mechanisms may include, but are not limited to: CodeDivision Multiple Access (CDMA), Orthogonal Frequency Division MultipleAccess (OFDMA), Time Division Multiple Access (TDMA), Wavelettechnologies, and/or the like. Hybrid transmission mechanisms such asTDMA/CDMA, and OFDM/CDMA may also be employed. Various modulationschemes may be applied for signal transmission in the physical layer.Examples of modulation schemes include, but are not limited to: phase,amplitude, code, a combination of these, and/or the like. An exampleradio transmission method may implement Quadrature Amplitude Modulation(QAM) using Binary Phase Shift Keying (BPSK), Quadrature Phase ShiftKeying (QPSK), 16-QAM, 64-QAM, 256-QAM, and/or the like. Physical radiotransmission may be enhanced by dynamically or semi-dynamically changingthe modulation and coding scheme depending on transmission requirementsand radio conditions.

FIG. 1 is an example Radio Access Network (RAN) architecture as per anaspect of an embodiment of the present disclosure. As illustrated inthis example, a RAN node may be a next generation Node B (gNB) (e.g.120A, 120B) providing New Radio (NR) user plane and control planeprotocol terminations towards a first wireless device (e.g. 110A). In anexample, a RAN node may be a next generation evolved Node B (ng-eNB)(e.g. 120C, 120D), providing Evolved UMTS Terrestrial Radio Access(E-UTRA) user plane and control plane protocol terminations towards asecond wireless device (e.g. 110B). The first wireless device maycommunicate with a gNB over a Uu interface. The second wireless devicemay communicate with a ng-eNB over a Uu interface.

A gNB or an ng-eNB may host functions such as radio resource managementand scheduling, IP header compression, encryption and integrityprotection of data, selection of Access and Mobility Management Function(AMF) at User Equipment (UE) attachment, routing of user plane andcontrol plane data, connection setup and release, scheduling andtransmission of paging messages (originated from the AMF), schedulingand transmission of system broadcast information (originated from theAMF or Operation and Maintenance (O&M)), measurement and measurementreporting configuration, transport level packet marking in the uplink,session management, support of network slicing, Quality of Service (QoS)flow management and mapping to data radio bearers, support of UEs inRRC_INACTIVE state, distribution function for Non-Access Stratum (NAS)messages, RAN sharing, dual connectivity or tight interworking betweenNR and E-UTRA.

In an example, one or more gNBs and/or one or more ng-eNBs may beinterconnected with each other by means of Xn interface. A gNB or anng-eNB may be connected by means of NG interfaces to 5G Core Network(5GC). In an example, 5GC may comprise one or more AMF/User PlanFunction (UPF) functions (e.g. 130A or 130B). A gNB or an ng-eNB may beconnected to a UPF by means of an NG-User plane (NG-U) interface. TheNG-U interface may provide delivery (e.g. non-guaranteed delivery) ofuser plane Protocol Data Units (PDUs) between a RAN node and the UPF. AgNB or an ng-eNB may be connected to an AMF by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide functions such asNG interface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, configurationtransfer or warning message transmission.

In an example, a UPF may host functions such as anchor point forintra-/inter-Radio Access Technology (RAT) mobility (when applicable),external PDU session point of interconnect to data network, packetrouting and forwarding, packet inspection and user plane part of policyrule enforcement, traffic usage reporting, uplink classifier to supportrouting traffic flows to a data network, branching point to supportmulti-homed PDU session, QoS handling for user plane, e.g. packetfiltering, gating, Uplink (UL)/Downlink (DL) rate enforcement, uplinktraffic verification (e.g. Service Data Flow (SDF) to QoS flow mapping),downlink packet buffering and/or downlink data notification triggering.

In an example, an AMF may host functions such as NAS signalingtermination, NAS signaling security, Access Stratum (AS) securitycontrol, inter Core Network (CN) node signaling for mobility between3^(rd) Generation Partnership Project (3GPP) access networks, idle modeUE reachability (e.g., control and execution of paging retransmission),registration area management, support of intra-system and inter-systemmobility, access authentication, access authorization including check ofroaming rights, mobility management control (subscription and policies),support of network slicing and/or Session Management Function (SMF)selection.

FIG. 2A is an example user plane protocol stack, where Service DataAdaptation Protocol (SDAP) (e.g. 211 and 221), Packet Data ConvergenceProtocol (PDCP) (e.g. 212 and 222), Radio Link Control (RLC) (e.g. 213and 223) and Media Access Control (MAC) (e.g. 214 and 224) sublayers andPhysical (PHY) (e.g. 215 and 225) layer may be terminated in wirelessdevice (e.g. 110) and gNB (e.g. 120) on the network side. In an example,a PHY layer provides transport services to higher layers (e.g. MAC, RRC,etc). In an example, services and functions of a MAC sublayer maycomprise mapping between logical channels and transport channels,multiplexing/demultiplexing of MAC Service Data Units (SDUs) belongingto one or different logical channels into/from Transport Blocks (TBs)delivered to/from the PHY layer, scheduling information reporting, errorcorrection through Hybrid Automatic Repeat request (HARQ) (e.g. one HARQentity per carrier in case of Carrier Aggregation (CA)), priorityhandling between UEs by means of dynamic scheduling, priority handlingbetween logical channels of one UE by means of logical channelprioritization, and/or padding. A MAC entity may support one or multiplenumerologies and/or transmission timings. In an example, mappingrestrictions in a logical channel prioritization may control whichnumerology and/or transmission timing a logical channel may use. In anexample, an RLC sublayer may supports transparent mode (TM),unacknowledged mode (UM) and acknowledged mode (AM) transmission modes.The RLC configuration may be per logical channel with no dependency onnumerologies and/or Transmission Time Interval (TTI) durations. In anexample, Automatic Repeat Request (ARQ) may operate on any of thenumerologies and/or TTI durations the logical channel is configuredwith. In an example, services and functions of the PDCP layer for theuser plane may comprise sequence numbering, header compression anddecompression, transfer of user data, reordering and duplicatedetection, PDCP PDU routing (e.g. in case of split bearers),retransmission of PDCP SDUs, ciphering, deciphering and integrityprotection, PDCP SDU discard, PDCP re-establishment and data recoveryfor RLC AM, and/or duplication of PDCP PDUs. In an example, services andfunctions of SDAP may comprise mapping between a QoS flow and a dataradio bearer. In an example, services and functions of SDAP may comprisemapping Quality of Service Indicator (QFI) in DL and UL packets. In anexample, a protocol entity of SDAP may be configured for an individualPDU session.

FIG. 2B is an example control plane protocol stack where PDCP (e.g. 233and 242), RLC (e.g. 234 and 243) and MAC (e.g. 235 and 244) sublayersand PHY (e.g. 236 and 245) layer may be terminated in wireless device(e.g. 110) and gNB (e.g. 120) on a network side and perform service andfunctions described above. In an example, RRC (e.g. 232 and 241) may beterminated in a wireless device and a gNB on a network side. In anexample, services and functions of RRC may comprise broadcast of systeminformation related to AS and NAS, paging initiated by 5GC or RAN,establishment, maintenance and release of an RRC connection between theUE and RAN, security functions including key management, establishment,configuration, maintenance and release of Signaling Radio Bearers (SRBs)and Data Radio Bearers (DRBs), mobility functions, QoS managementfunctions, UE measurement reporting and control of the reporting,detection of and recovery from radio link failure, and/or NAS messagetransfer to/from NAS from/to a UE. In an example, NAS control protocol(e.g. 231 and 251) may be terminated in the wireless device and AMF(e.g. 130) on a network side and may perform functions such asauthentication, mobility management between a UE and a AMF for 3GPPaccess and non-3GPP access, and session management between a UE and aSMF for 3GPP access and non-3GPP access.

In an example, a base station may configure a plurality of logicalchannels for a wireless device. A logical channel in the plurality oflogical channels may correspond to a radio bearer and the radio bearermay be associated with a QoS requirement. In an example, a base stationmay configure a logical channel to be mapped to one or moreTTIs/numerologies in a plurality of TTIs/numerologies. The wirelessdevice may receive a Downlink Control Information (DCI) via PhysicalDownlink Control CHannel (PDCCH) indicating an uplink grant. In anexample, the uplink grant may be for a first TTI/numerology and mayindicate uplink resources for transmission of a transport block. Thebase station may configure each logical channel in the plurality oflogical channels with one or more parameters to be used by a logicalchannel prioritization procedure at the MAC layer of the wirelessdevice. The one or more parameters may comprise priority, prioritizedbit rate, etc. A logical channel in the plurality of logical channelsmay correspond to one or more buffers comprising data associated withthe logical channel. The logical channel prioritization procedure mayallocate the uplink resources to one or more first logical channels inthe plurality of logical channels and/or one or more MAC ControlElements (CEs). The one or more first logical channels may be mapped tothe first TTI/numerology. The MAC layer at the wireless device maymultiplex one or more MAC CEs and/or one or more MAC SDUs (e.g., logicalchannel) in a MAC PDU (e.g., transport block). In an example, the MACPDU may comprise a MAC header comprising a plurality of MAC sub-headers.A MAC sub-header in the plurality of MAC sub-headers may correspond to aMAC CE or a MAC SUD (logical channel) in the one or more MAC CEs and/orone or more MAC SDUs. In an example, a MAC CE or a logical channel maybe configured with a Logical Channel IDentifier (LCID). In an example,LCID for a logical channel or a MAC CE may be fixed/pre-configured. Inan example, LCID for a logical channel or MAC CE may be configured forthe wireless device by the base station. The MAC sub-headercorresponding to a MAC CE or a MAC SDU may comprise LCID associated withthe MAC CE or the MAC SDU.

In an example, a base station may activate and/or deactivate and/orimpact one or more processes (e.g., set values of one or more parametersof the one or more processes or start and/or stop one or more timers ofthe one or more processes) at the wireless device by employing one ormore MAC commands. The one or more MAC commands may comprise one or moreMAC control elements. In an example, the one or more processes maycomprise activation and/or deactivation of PDCP packet duplication forone or more radio bearers. The base station may transmit a MAC CEcomprising one or more fields, the values of the fields indicatingactivation and/or deactivation of PDCP duplication for the one or moreradio bearers. In an example, the one or more processes may compriseChannel State Information (CSI) transmission of on one or more cells.The base station may transmit one or more MAC CEs indicating activationand/or deactivation of the CSI transmission on the one or more cells. Inan example, the one or more processes may comprise activation ordeactivation of one or more secondary cells. In an example, the basestation may transmit a MA CE indicating activation or deactivation ofone or more secondary cells. In an example, the base station maytransmit one or more MAC CEs indicating starting and/or stopping one ormore Discontinuous Reception (DRX) timers at the wireless device. In anexample, the base station may transmit one or more MAC CEs indicatingone or more timing advance values for one or more Timing Advance Groups(TAGs).

FIG. 3 is a block diagram of base stations (base station 1, 120A, andbase station 2, 120B) and a wireless device 110. A wireless device maybe called an UE. A base station may be called a NB, eNB, gNB, and/orng-eNB. In an example, a wireless device and/or a base station may actas a relay node. The base station 1, 120A, may comprise at least onecommunication interface 320A (e.g. a wireless modem, an antenna, a wiredmodem, and/or the like), at least one processor 321A, and at least oneset of program code instructions 323A stored in non-transitory memory322A and executable by the at least one processor 321A. The base station2, 120B, may comprise at least one communication interface 320B, atleast one processor 321B, and at least one set of program codeinstructions 323B stored in non-transitory memory 322B and executable bythe at least one processor 321B.

A base station may comprise many sectors for example: 1, 2, 3, 4, or 6sectors. A base station may comprise many cells, for example, rangingfrom 1 to 50 cells or more. A cell may be categorized, for example, as aprimary cell or secondary cell. At Radio Resource Control (RRC)connection establishment/re-establishment/handover, one serving cell mayprovide the NAS (non-access stratum) mobility information (e.g. TrackingArea Identifier (TAI)). At RRC connection re-establishment/handover, oneserving cell may provide the security input. This cell may be referredto as the Primary Cell (PCell). In the downlink, a carrier correspondingto the PCell may be a DL Primary Component Carrier (PCC), while in theuplink, a carrier may be an UL PCC. Depending on wireless devicecapabilities, Secondary Cells (SCells) may be configured to formtogether with a PCell a set of serving cells. In a downlink, a carriercorresponding to an SCell may be a downlink secondary component carrier(DL SCC), while in an uplink, a carrier may be an uplink secondarycomponent carrier (UL SCC). An SCell may or may not have an uplinkcarrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and a cell index. A carrier (downlinkor uplink) may belong to one cell. The cell ID or cell index may alsoidentify the downlink carrier or uplink carrier of the cell (dependingon the context it is used). In the disclosure, a cell ID may be equallyreferred to a carrier ID, and a cell index may be referred to a carrierindex. In an implementation, a physical cell ID or a cell index may beassigned to a cell. A cell ID may be determined using a synchronizationsignal transmitted on a downlink carrier. A cell index may be determinedusing RRC messages. For example, when the disclosure refers to a firstphysical cell ID for a first downlink carrier, the disclosure may meanthe first physical cell ID is for a cell comprising the first downlinkcarrier. The same concept may apply to, for example, carrier activation.When the disclosure indicates that a first carrier is activated, thespecification may equally mean that a cell comprising the first carrieris activated.

A base station may transmit to a wireless device one or more messages(e.g. RRC messages) comprising a plurality of configuration parametersfor one or more cells. One or more cells may comprise at least oneprimary cell and at least one secondary cell. In an example, an RRCmessage may be broadcasted or unicasted to the wireless device. In anexample, configuration parameters may comprise common parameters anddedicated parameters.

Services and/or functions of an RRC sublayer may comprise at least oneof: broadcast of system information related to AS and NAS; paginginitiated by 5GC and/or NG-RAN; establishment, maintenance, and/orrelease of an RRC connection between a wireless device and NG-RAN, whichmay comprise at least one of addition, modification and release ofcarrier aggregation; or addition, modification, and/or release of dualconnectivity in NR or between E-UTRA and NR. Services and/or functionsof an RRC sublayer may further comprise at least one of securityfunctions comprising key management; establishment, configuration,maintenance, and/or release of Signaling Radio Bearers (SRBs) and/orData Radio Bearers (DRBs); mobility functions which may comprise atleast one of a handover (e.g. intra NR mobility or inter-RAT mobility)and a context transfer; or a wireless device cell selection andreselection and control of cell selection and reselection. Servicesand/or functions of an RRC sublayer may further comprise at least one ofQoS management functions; a wireless device measurementconfiguration/reporting; detection of and/or recovery from radio linkfailure; or NAS message transfer to/from a core network entity (e.g.AMF, Mobility Management Entity (MME)) from/to the wireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive stateand/or an RRC_Connected state for a wireless device. In an RRC_Idlestate, a wireless device may perform at least one of: Public Land MobileNetwork (PLMN) selection; receiving broadcasted system information; cellselection/re-selection; monitoring/receiving a paging for mobileterminated data initiated by 5GC; paging for mobile terminated data areamanaged by 5GC; or DRX for CN paging configured via NAS. In anRRC_Inactive state, a wireless device may perform at least one of:receiving broadcasted system information; cell selection/re-selection;monitoring/receiving a RAN/CN paging initiated by NG-RAN/5GC; RAN-basednotification area (RNA) managed by NG-RAN; or DRX for RAN/CN pagingconfigured by NG-RAN/NAS. In an RRC_Idle state of a wireless device, abase station (e.g. NG-RAN) may keep a 5GC-NG-RAN connection (bothC/U-planes) for the wireless device; and/or store a UE AS context forthe wireless device. In an RRC_Connected state of a wireless device, abase station (e.g. NG-RAN) may perform at least one of: establishment of5GC-NG-RAN connection (both C/U-planes) for the wireless device; storinga UE AS context for the wireless device; transmit/receive of unicastdata to/from the wireless device; or network-controlled mobility basedon measurement results received from the wireless device. In anRRC_Connected state of a wireless device, an NG-RAN may know a cell thatthe wireless device belongs to.

System information (SI) may be divided into minimum SI and other SI. Theminimum SI may be periodically broadcast. The minimum SI may comprisebasic information required for initial access and information foracquiring any other SI broadcast periodically or provisioned on-demand,i.e. scheduling information. The other SI may either be broadcast, or beprovisioned in a dedicated manner, either triggered by a network or uponrequest from a wireless device. A minimum SI may be transmitted via twodifferent downlink channels using different messages (e.g.MasterInformationBlock and SystemInformationBlockType1). An other SI maybe transmitted via SystemInformationBlockType2. For a wireless device inan RRC_Connected state, dedicated RRC signalling may be employed for therequest and delivery of the other SI. For the wireless device in theRRC_Idle state and/or the RRC_Inactive state, the request may trigger arandom-access procedure.

A wireless device may report its radio access capability informationwhich may be static. A base station may request what capabilities for awireless device to report based on band information. When allowed by anetwork, a temporary capability restriction request may be sent by thewireless device to signal the limited availability of some capabilities(e.g. due to hardware sharing, interference or overheating) to the basestation. The base station may confirm or reject the request. Thetemporary capability restriction may be transparent to 5GC (e.g., staticcapabilities may be stored in 5GC).

When CA is configured, a wireless device may have an RRC connection witha network. At RRC connection establishment/re-establishment/handoverprocedure, one serving cell may provide NAS mobility information, and atRRC connection re-establishment/handover, one serving cell may provide asecurity input. This cell may be referred to as the PCell. Depending onthe capabilities of the wireless device, SCells may be configured toform together with the PCell a set of serving cells. The configured setof serving cells for the wireless device may comprise one PCell and oneor more SCells.

The reconfiguration, addition and removal of SCells may be performed byRRC. At intra-NR handover, RRC may also add, remove, or reconfigureSCells for usage with the target PCell. When adding a new SCell,dedicated RRC signalling may be employed to send all required systeminformation of the SCell i.e. while in connected mode, wireless devicesmay not need to acquire broadcasted system information directly from theSCells.

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g. to establish, modify and/or release RBs,to perform handover, to setup, modify, and/or release measurements, toadd, modify, and/or release SCells and cell groups). As part of the RRCconnection reconfiguration procedure, NAS dedicated information may betransferred from the network to the wireless device. TheRRCConnectionReconfiguration message may be a command to modify an RRCconnection. It may convey information for measurement configuration,mobility control, radio resource configuration (e.g. RBs, MAC mainconfiguration and physical channel configuration) comprising anyassociated dedicated NAS information and security configuration. If thereceived RRC Connection Reconfiguration message includes thesCellToReleaseList, the wireless device may perform an SCell release. Ifthe received RRC Connection Reconfiguration message includes thesCellToAddModList, the wireless device may perform SCell additions ormodification.

An RRC connection establishment (or reestablishment, resume) proceduremay be to establish (or reestablish, resume) an RRC connection. an RRCconnection establishment procedure may comprise SRB1 establishment. TheRRC connection establishment procedure may be used to transfer theinitial NAS dedicated information/message from a wireless device toE-UTRAN. The RRCConnectionReestablishment message may be used tore-establish SRB1.

A measurement report procedure may be to transfer measurement resultsfrom a wireless device to NG-RAN. The wireless device may initiate ameasurement report procedure after successful security activation. Ameasurement report message may be employed to transmit measurementresults.

The wireless device 110 may comprise at least one communicationinterface 310 (e.g. a wireless modem, an antenna, and/or the like), atleast one processor 314, and at least one set of program codeinstructions 316 stored in non-transitory memory 315 and executable bythe at least one processor 314. The wireless device 110 may furthercomprise at least one of at least one speaker/microphone 311, at leastone keypad 312, at least one display/touchpad 313, at least one powersource 317, at least one global positioning system (GPS) chipset 318,and other peripherals 319.

The processor 314 of the wireless device 110, the processor 321A of thebase station 1 120A, and/or the processor 321B of the base station 2120B may comprise at least one of a general-purpose processor, a digitalsignal processor (DSP), a controller, a microcontroller, an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) and/or other programmable logic device, discrete gate and/ortransistor logic, discrete hardware components, and the like. Theprocessor 314 of the wireless device 110, the processor 321A in basestation 1 120A, and/or the processor 321B in base station 2 120B mayperform at least one of signal coding/processing, data processing, powercontrol, input/output processing, and/or any other functionality thatmay enable the wireless device 110, the base station 1 120A and/or thebase station 2 120B to operate in a wireless environment.

The processor 314 of the wireless device 110 may be connected to thespeaker/microphone 311, the keypad 312, and/or the display/touchpad 313.The processor 314 may receive user input data from and/or provide useroutput data to the speaker/microphone 311, the keypad 312, and/or thedisplay/touchpad 313. The processor 314 in the wireless device 110 mayreceive power from the power source 317 and/or may be configured todistribute the power to the other components in the wireless device 110.The power source 317 may comprise at least one of one or more dry cellbatteries, solar cells, fuel cells, and the like. The processor 314 maybe connected to the GPS chipset 318. The GPS chipset 318 may beconfigured to provide geographic location information of the wirelessdevice 110.

The processor 314 of the wireless device 110 may further be connected toother peripherals 319, which may comprise one or more software and/orhardware modules that provide additional features and/orfunctionalities. For example, the peripherals 319 may comprise at leastone of an accelerometer, a satellite transceiver, a digital camera, auniversal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, and thelike.

The communication interface 320A of the base station 1, 120A, and/or thecommunication interface 320B of the base station 2, 120B, may beconfigured to communicate with the communication interface 310 of thewireless device 110 via a wireless link 330A and/or a wireless link 330Brespectively. In an example, the communication interface 320A of thebase station 1, 120A, may communicate with the communication interface320B of the base station 2 and other RAN and core network nodes.

The wireless link 330A and/or the wireless link 330B may comprise atleast one of a bi-directional link and/or a directional link. Thecommunication interface 310 of the wireless device 110 may be configuredto communicate with the communication interface 320A of the base station1 120A and/or with the communication interface 320B of the base station2 120B. The base station 1 120A and the wireless device 110 and/or thebase station 2 120B and the wireless device 110 may be configured tosend and receive transport blocks via the wireless link 330A and/or viathe wireless link 330B, respectively. The wireless link 330A and/or thewireless link 330B may employ at least one frequency carrier. Accordingto some of various aspects of embodiments, transceiver(s) may beemployed. A transceiver may be a device that comprises both atransmitter and a receiver. Transceivers may be employed in devices suchas wireless devices, base stations, relay nodes, and/or the like.Example embodiments for radio technology implemented in thecommunication interface 310, 320A, 320B and the wireless link 330A, 330Bare illustrated in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 6, FIG. 7A,FIG. 7B, FIG. 8, and associated text.

In an example, other nodes in a wireless network (e.g. AMF, UPF, SMF,etc) may comprise one or more communication interfaces, one or moreprocessors, and memory storing instructions.

A node (e.g. wireless device, base station, AMF, SMF, UPF, servers,switches, antennas, and/or the like) may comprise one or moreprocessors, and memory storing instructions that when executed by theone or more processors causes the node to perform certain processesand/or functions. Example embodiments may enable operation ofsingle-carrier and/or multi-carrier communications. Other exampleembodiments may comprise a non-transitory tangible computer readablemedia comprising instructions executable by one or more processors tocause operation of single-carrier and/or multi-carrier communications.Yet other example embodiments may comprise an article of manufacturethat comprises a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a node to enable operation ofsingle-carrier and/or multi-carrier communications. The node may includeprocessors, memory, interfaces, and/or the like.

An interface may comprise at least one of a hardware interface, afirmware interface, a software interface, and/or a combination thereof.The hardware interface may comprise connectors, wires, electronicdevices such as drivers, amplifiers, and/or the like. The softwareinterface may comprise code stored in a memory device to implementprotocol(s), protocol layers, communication drivers, device drivers,combinations thereof, and/or the like. The firmware interface maycomprise a combination of embedded hardware and code stored in and/or incommunication with a memory device to implement connections, electronicdevice operations, protocol(s), protocol layers, communication drivers,device drivers, hardware operations, combinations thereof, and/or thelike.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplinkand downlink signal transmission as per an aspect of an embodiment ofthe present disclosure. FIG. 4A shows an example uplink transmitter forat least one physical channel A baseband signal representing a physicaluplink shared channel may perform one or more functions. The one or morefunctions may comprise at least one of: scrambling; modulation ofscrambled bits to generate complex-valued symbols; mapping of thecomplex-valued modulation symbols onto one or several transmissionlayers; transform precoding to generate complex-valued symbols;precoding of the complex-valued symbols; mapping of precodedcomplex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 4A. These functions are illustrated as examples andit is anticipated that other mechanisms may be implemented in variousembodiments.

An example structure for modulation and up-conversion to the carrierfrequency of the complex-valued SC-FDMA or CP-OFDM baseband signal foran antenna port and/or the complex-valued Physical Random Access CHannel(PRACH) baseband signal is shown in FIG. 4B. Filtering may be employedprior to transmission.

An example structure for downlink transmissions is shown in FIG. 4C. Thebaseband signal representing a downlink physical channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

In an example, a gNB may transmit a first symbol and a second symbol onan antenna port, to a wireless device. The wireless device may infer thechannel (e.g., fading gain, multipath delay, etc.) for conveying thesecond symbol on the antenna port, from the channel for conveying thefirst symbol on the antenna port. In an example, a first antenna portand a second antenna port may be quasi co-located if one or morelarge-scale properties of the channel over which a first symbol on thefirst antenna port is conveyed may be inferred from the channel overwhich a second symbol on a second antenna port is conveyed. The one ormore large-scale properties may comprise at least one of: delay spread;doppler spread; doppler shift; average gain; average delay; and/orspatial Receiving (Rx) parameters.

An example modulation and up-conversion to the carrier frequency of thecomplex-valued OFDM baseband signal for an antenna port is shown in FIG.4D. Filtering may be employed prior to transmission.

FIG. 5A is a diagram of an example uplink channel mapping and exampleuplink physical signals. FIG. 5B is a diagram of an example downlinkchannel mapping and a downlink physical signals. In an example, aphysical layer may provide one or more information transfer services toa MAC and/or one or more higher layers. For example, the physical layermay provide the one or more information transfer services to the MAC viaone or more transport channels. An information transfer service mayindicate how and with what characteristics data are transferred over theradio interface.

In an example embodiment, a radio network may comprise one or moredownlink and/or uplink transport channels. For example, a diagram inFIG. 5A shows example uplink transport channels comprising Uplink-SharedCHannel (UL-SCH) 501 and Random Access CHannel (RACH) 502. A diagram inFIG. 5B shows example downlink transport channels comprisingDownlink-Shared CHannel (DL-SCH) 511, Paging CHannel (PCH) 512, andBroadcast CHannel (BCH) 513. A transport channel may be mapped to one ormore corresponding physical channels. For example, UL-SCH 501 may bemapped to Physical Uplink Shared CHannel (PUSCH) 503. RACH 502 may bemapped to PRACH 505. DL-SCH 511 and PCH 512 may be mapped to PhysicalDownlink Shared CHannel (PDSCH) 514. BCH 513 may be mapped to PhysicalBroadcast CHannel (PBCH) 516.

There may be one or more physical channels without a correspondingtransport channel. The one or more physical channels may be employed forUplink Control Information (UCI) 509 and/or Downlink Control Information(DCI) 517. For example, Physical Uplink Control CHannel (PUCCH) 504 maycarry UCI 509 from a UE to a base station. For example, PhysicalDownlink Control CHannel (PDCCH) 515 may carry DCI 517 from a basestation to a UE. NR may support UCI 509 multiplexing in PUSCH 503 whenUCI 509 and PUSCH 503 transmissions may coincide in a slot at least inpart. The UCI 509 may comprise at least one of CSI, Acknowledgement(ACK)/Negative Acknowledgement (NACK), and/or scheduling request. TheDCI 517 on PDCCH 515 may indicate at least one of following: one or moredownlink assignments and/or one or more uplink scheduling grants

In uplink, a UE may transmit one or more Reference Signals (RSs) to abase station. For example, the one or more RSs may be at least one ofDemodulation-RS (DM-RS) 506, Phase Tracking-RS (PT-RS) 507, and/orSounding RS (SRS) 508. In downlink, a base station may transmit (e.g.,unicast, multicast, and/or broadcast) one or more RSs to a UE. Forexample, the one or more RSs may be at least one of PrimarySynchronization Signal (PSS)/Secondary Synchronization Signal (SSS) 521,CSI-RS 522, DM-RS 523, and/or PT-RS 524.

In an example, a UE may transmit one or more uplink DM-RSs 506 to a basestation for channel estimation, for example, for coherent demodulationof one or more uplink physical channels (e.g., PUSCH 503 and/or PUCCH504). For example, a UE may transmit a base station at least one uplinkDM-RS 506 with PUSCH 503 and/or PUCCH 504, wherein the at least oneuplink DM-RS 506 may be spanning a same frequency range as acorresponding physical channel. In an example, a base station mayconfigure a UE with one or more uplink DM-RS configurations. At leastone DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may beconfigured to transmit at one or more symbols of a PUSCH and/or PUCCH. Abase station may semi-statically configure a UE with a maximum number offront-loaded DM-RS symbols for PUSCH and/or PUCCH. For example, a UE mayschedule a single-symbol DM-RS and/or double symbol DM-RS based on amaximum number of front-loaded DM-RS symbols, wherein a base station mayconfigure the UE with one or more additional uplink DM-RS for PUSCHand/or PUCCH. A new radio network may support, e.g., at least forCP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RSlocation, DM-RS pattern, and/or scrambling sequence may be same ordifferent.

In an example, whether uplink PT-RS 507 is present or not may depend ona RRC configuration. For example, a presence of uplink PT-RS may beUE-specifically configured. For example, a presence and/or a pattern ofuplink PT-RS 507 in a scheduled resource may be UE-specificallyconfigured by a combination of RRC signaling and/or association with oneor more parameters employed for other purposes (e.g., Modulation andCoding Scheme (MCS)) which may be indicated by DCI. When configured, adynamic presence of uplink PT-RS 507 may be associated with one or moreDCI parameters comprising at least MCS. A radio network may supportplurality of uplink PT-RS densities defined in time/frequency domain.When present, a frequency domain density may be associated with at leastone configuration of a scheduled bandwidth. A UE may assume a sameprecoding for a DMRS port and a PT-RS port. A number of PT-RS ports maybe fewer than a number of DM-RS ports in a scheduled resource. Forexample, uplink PT-RS 507 may be confined in the scheduledtime/frequency duration for a UE.

In an example, a UE may transmit SRS 508 to a base station for channelstate estimation to support uplink channel dependent scheduling and/orlink adaptation. For example, SRS 508 transmitted by a UE may allow fora base station to estimate an uplink channel state at one or moredifferent frequencies. A base station scheduler may employ an uplinkchannel state to assign one or more resource blocks of good quality foran uplink PUSCH transmission from a UE. A base station maysemi-statically configure a UE with one or more SRS resource sets. Foran SRS resource set, a base station may configure a UE with one or moreSRS resources. An SRS resource set applicability may be configured by ahigher layer (e.g., RRC) parameter. For example, when a higher layerparameter indicates beam management, a SRS resource in each of one ormore SRS resource sets may be transmitted at a time instant. A UE maytransmit one or more SRS resources in different SRS resource setssimultaneously. A new radio network may support aperiodic, periodicand/or semi-persistent SRS transmissions. A UE may transmit SRSresources based on one or more trigger types, wherein the one or moretrigger types may comprise higher layer signaling (e.g., RRC) and/or oneor more DCI formats (e.g., at least one DCI format may be employed for aUE to select at least one of one or more configured SRS resource sets.An SRS trigger type 0 may refer to an SRS triggered based on a higherlayer signaling. An SRS trigger type 1 may refer to an SRS triggeredbased on one or more DCI formats. In an example, when PUSCH 503 and SRS508 are transmitted in a same slot, a UE may be configured to transmitSRS 508 after a transmission of PUSCH 503 and corresponding uplink DM-RS506.

In an example, a base station may semi-statically configure a UE withone or more SRS configuration parameters indicating at least one offollowing: a SRS resource configuration identifier, a number of SRSports, time domain behavior of SRS resource configuration (e.g., anindication of periodic, semi-persistent, or aperiodic SRS), slot(mini-slot, and/or subframe) level periodicity and/or offset for aperiodic and/or aperiodic SRS resource, a number of OFDM symbols in aSRS resource, starting OFDM symbol of a SRS resource, a SRS bandwidth, afrequency hopping bandwidth, a cyclic shift, and/or a SRS sequence ID.

In an example, in a time domain, an SS/PBCH block may comprise one ormore OFDM symbols (e.g., 4 OFDM symbols numbered in increasing orderfrom 0 to 3) within the SS/PBCH block. An SS/PBCH block may comprisePSS/SSS 521 and PBCH 516. In an example, in the frequency domain, anSS/PBCH block may comprise one or more contiguous subcarriers (e.g., 240contiguous subcarriers with the subcarriers numbered in increasing orderfrom 0 to 239) within the SS/PBCH block. For example, a PSS/SSS 521 mayoccupy 1 OFDM symbol and 127 subcarriers. For example, PBCH 516 may spanacross 3 OFDM symbols and 240 subcarriers. A UE may assume that one ormore SS/PBCH blocks transmitted with a same block index may be quasico-located, e.g., with respect to Doppler spread, Doppler shift, averagegain, average delay, and spatial Rx parameters. A UE may not assumequasi co-location for other SS/PBCH block transmissions. A periodicityof an SS/PBCH block may be configured by a radio network (e.g., by anRRC signaling) and one or more time locations where the SS/PBCH blockmay be sent may be determined by sub-carrier spacing. In an example, aUE may assume a band-specific sub-carrier spacing for an SS/PBCH blockunless a radio network has configured a UE to assume a differentsub-carrier spacing.

In an example, downlink CSI-RS 522 may be employed for a UE to acquirechannel state information. A radio network may support periodic,aperiodic, and/or semi-persistent transmission of downlink CSI-RS 522.For example, a base station may semi-statically configure and/orreconfigure a UE with periodic transmission of downlink CSI-RS 522. Aconfigured CSI-RS resources may be activated ad/or deactivated. Forsemi-persistent transmission, an activation and/or deactivation ofCSI-RS resource may be triggered dynamically. In an example, CSI-RSconfiguration may comprise one or more parameters indicating at least anumber of antenna ports. For example, a base station may configure a UEwith 32 ports. A base station may semi-statically configure a UE withone or more CSI-RS resource sets. One or more CSI-RS resources may beallocated from one or more CSI-RS resource sets to one or more UEs. Forexample, a base station may semi-statically configure one or moreparameters indicating CSI RS resource mapping, for example, time-domainlocation of one or more CSI-RS resources, a bandwidth of a CSI-RSresource, and/or a periodicity. In an example, a UE may be configured toemploy a same OFDM symbols for downlink CSI-RS 522 and control resourceset (coreset) when the downlink CSI-RS 522 and coreset are spatiallyquasi co-located and resource elements associated with the downlinkCSI-RS 522 are the outside of PRBs configured for coreset. In anexample, a UE may be configured to employ a same OFDM symbols fordownlink CSI-RS 522 and SSB/PBCH when the downlink CSI-RS 522 andSSB/PBCH are spatially quasi co-located and resource elements associatedwith the downlink CSI-RS 522 are the outside of PRBs configured forSSB/PBCH.

In an example, a UE may transmit one or more downlink DM-RSs 523 to abase station for channel estimation, for example, for coherentdemodulation of one or more downlink physical channels (e.g., PDSCH514). For example, a radio network may support one or more variableand/or configurable DM-RS patterns for data demodulation. At least onedownlink DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). A base station may semi-staticallyconfigure a UE with a maximum number of front-loaded DM-RS symbols forPDSCH 514. For example, a DM-RS configuration may support one or moreDM-RS ports. For example, for single user-MIMO, a DM-RS configurationmay support at least 8 orthogonal downlink DM-RS ports. For example, formultiuser-MIMO, a DM-RS configuration may support 12 orthogonal downlinkDM-RS ports. A radio network may support, e.g., at least for CP-OFDM, acommon DM-RS structure for DL and UL, wherein a DM-RS location, DM-RSpattern, and/or scrambling sequence may be same or different.

In an example, whether downlink PT-RS 524 is present or not may dependon a RRC configuration. For example, a presence of downlink PT-RS 524may be UE-specifically configured. For example, a presence and/or apattern of downlink PT-RS 524 in a scheduled resource may beUE-specifically configured by a combination of RRC signaling and/orassociation with one or more parameters employed for other purposes(e.g., MCS) which may be indicated by DCI. When configured, a dynamicpresence of downlink PT-RS 524 may be associated with one or more DCIparameters comprising at least MCS. A radio network may supportplurality of PT-RS densities defined in time/frequency domain. Whenpresent, a frequency domain density may be associated with at least oneconfiguration of a scheduled bandwidth. A UE may assume a same precodingfor a DMRS port and a PT-RS port. A number of PT-RS ports may be fewerthan a number of DM-RS ports in a scheduled resource. For example,downlink PT-RS 524 may be confined in the scheduled time/frequencyduration for a UE.

FIG. 6 is a diagram depicting an example frame structure for a carrieras per an aspect of an embodiment of the present disclosure. Amulticarrier OFDM communication system may include one or more carriers,for example, ranging from 1 to 32 carriers, in case of carrieraggregation, or ranging from 1 to 64 carriers, in case of dualconnectivity. Different radio frame structures may be supported (e.g.,for FDD and for TDD duplex mechanisms). FIG. 6 shows an example framestructure. Downlink and uplink transmissions may be organized into radioframes 601. In this example, radio frame duration is 10 ms. In thisexample, a 10 ms radio frame 601 may be divided into ten equally sizedsubframes 602 with 1 ms duration. Subframe(s) may comprise one or moreslots (e.g. slots 603 and 605) depending on subcarrier spacing and/or CPlength. For example, a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz,240 kHz and 480 kHz subcarrier spacing may comprise one, two, four,eight, sixteen and thirty-two slots, respectively. In FIG. 6, a subframemay be divided into two equally sized slots 603 with 0.5 ms duration.For example, 10 subframes may be available for downlink transmission and10 subframes may be available for uplink transmissions in a 10 msinterval. Uplink and downlink transmissions may be separated in thefrequency domain. Slot(s) may include a plurality of OFDM symbols 604.The number of OFDM symbols 604 in a slot 605 may depend on the cyclicprefix length. For example, a slot may be 14 OFDM symbols for the samesubcarrier spacing of up to 480 kHz with normal CP. A slot may be 12OFDM symbols for the same subcarrier spacing of 60 kHz with extended CP.A slot may contain downlink, uplink, or a downlink part and an uplinkpart and/or alike.

FIG. 7A is a diagram depicting example sets of OFDM subcarriers as peran aspect of an embodiment of the present disclosure. In the example, agNB may communicate with a wireless device with a carrier with anexample channel bandwidth 700. Arrow(s) in the diagram may depict asubcarrier in a multicarrier OFDM system. The OFDM system may usetechnology such as OFDM technology, SC-FDMA technology, and/or the like.In an example, an arrow 701 shows a subcarrier transmitting informationsymbols. In an example, a subcarrier spacing 702, between two contiguoussubcarriers in a carrier, may be any one of 15 KHz, 30 KHz, 60 KHz, 120KHz, 240 KHz etc. In an example, different subcarrier spacing maycorrespond to different transmission numerologies. In an example, atransmission numerology may comprise at least: a numerology index; avalue of subcarrier spacing; a type of cyclic prefix (CP). In anexample, a gNB may transmit to/receive from a UE on a number ofsubcarriers 703 in a carrier. In an example, a bandwidth occupied by anumber of subcarriers 703 (transmission bandwidth) may be smaller thanthe channel bandwidth 700 of a carrier, due to guard band 704 and 705.In an example, a guard band 704 and 705 may be used to reduceinterference to and from one or more neighbor carriers. A number ofsubcarriers (transmission bandwidth) in a carrier may depend on thechannel bandwidth of the carrier and the subcarrier spacing. Forexample, a transmission bandwidth, for a carrier with 20 MHz channelbandwidth and 15 KHz subcarrier spacing, may be in number of 1024subcarriers.

In an example, a gNB and a wireless device may communicate with multipleCCs when configured with CA. In an example, different component carriersmay have different bandwidth and/or subcarrier spacing, if CA issupported. In an example, a gNB may transmit a first type of service toa UE on a first component carrier. The gNB may transmit a second type ofservice to the UE on a second component carrier. Different type ofservices may have different service requirement (e.g., data rate,latency, reliability), which may be suitable for transmission viadifferent component carrier having different subcarrier spacing and/orbandwidth. FIG. 7B shows an example embodiment. A first componentcarrier may comprise a first number of subcarriers 706 with a firstsubcarrier spacing 709. A second component carrier may comprise a secondnumber of subcarriers 707 with a second subcarrier spacing 710. A thirdcomponent carrier may comprise a third number of subcarriers 708 with athird subcarrier spacing 711. Carriers in a multicarrier OFDMcommunication system may be contiguous carriers, non-contiguouscarriers, or a combination of both contiguous and non-contiguouscarriers.

FIG. 8 is a diagram depicting OFDM radio resources as per an aspect ofan embodiment of the present disclosure. In an example, a carrier mayhave a transmission bandwidth 801. In an example, a resource grid may bein a structure of frequency domain 802 and time domain 803. In anexample, a resource grid may comprise a first number of OFDM symbols ina subframe and a second number of resource blocks, starting from acommon resource block indicated by higher-layer signaling (e.g. RRCsignaling), for a transmission numerology and a carrier. In an example,in a resource grid, a resource unit identified by a subcarrier index anda symbol index may be a resource element 805. In an example, a subframemay comprise a first number of OFDM symbols 807 depending on anumerology associated with a carrier. For example, when a subcarrierspacing of a numerology of a carrier is 15 KHz, a subframe may have 14OFDM symbols for a carrier. When a subcarrier spacing of a numerology is30 KHz, a subframe may have 28 OFDM symbols. When a subcarrier spacingof a numerology is 60 Khz, a subframe may have 56 OFDM symbols, etc. Inan example, a second number of resource blocks comprised in a resourcegrid of a carrier may depend on a bandwidth and a numerology of thecarrier.

As shown in FIG. 8, a resource block 806 may comprise 12 subcarriers. Inan example, multiple resource blocks may be grouped into a ResourceBlock Group (RBG) 804. In an example, a size of a RBG may depend on atleast one of: a RRC message indicating a RBG size configuration; a sizeof a carrier bandwidth; or a size of a bandwidth part of a carrier. Inan example, a carrier may comprise multiple bandwidth parts. A firstbandwidth part of a carrier may have different frequency location and/orbandwidth from a second bandwidth part of the carrier.

In an example, a gNB may transmit a downlink control informationcomprising a downlink or uplink resource block assignment to a wirelessdevice. A base station may transmit to or receive from, a wirelessdevice, data packets (e.g. transport blocks) scheduled and transmittedvia one or more resource blocks and one or more slots according toparameters in a downlink control information and/or RRC message(s). Inan example, a starting symbol relative to a first slot of the one ormore slots may be indicated to the wireless device. In an example, a gNBmay transmit to or receive from, a wireless device, data packetsscheduled on one or more RBGs and one or more slots.

In an example, a gNB may transmit a downlink control informationcomprising a downlink assignment to a wireless device via one or morePDCCHs. The downlink assignment may comprise parameters indicating atleast modulation and coding format; resource allocation; and/or HARQinformation related to DL-SCH. In an example, a resource allocation maycomprise parameters of resource block allocation; and/or slotallocation. In an example, a gNB may dynamically allocate resources to awireless device via a Cell-Radio Network Temporary Identifier (C-RNTI)on one or more PDCCHs. The wireless device may monitor the one or morePDCCHs in order to find possible allocation when its downlink receptionis enabled. The wireless device may receive one or more downlink datapackage on one or more PDSCH scheduled by the one or more PDCCHs, whensuccessfully detecting the one or more PDCCHs.

In an example, a gNB may allocate Configured Scheduling (CS) resourcesfor down link transmission to a wireless device. The gNB may transmitone or more RRC messages indicating a periodicity of the CS grant. ThegNB may transmit a DCI via a PDCCH addressed to a ConfiguredScheduling-RNTI (CS-RNTI) activating the CS resources. The DCI maycomprise parameters indicating that the downlink grant is a CS grant.The CS grant may be implicitly reused according to the periodicitydefined by the one or more RRC messages, until deactivated.

In an example, a gNB may transmit a downlink control informationcomprising an uplink grant to a wireless device via one or more PDCCHs.The uplink grant may comprise parameters indicating at least modulationand coding format; resource allocation; and/or HARQ information relatedto UL-SCH. In an example, a resource allocation may comprise parametersof resource block allocation; and/or slot allocation. In an example, agNB may dynamically allocate resources to a wireless device via a C-RNTIon one or more PDCCHs. The wireless device may monitor the one or morePDCCHs in order to find possible resource allocation. The wirelessdevice may transmit one or more uplink data package via one or morePUSCH scheduled by the one or more PDCCHs, when successfully detectingthe one or more PDCCHs.

In an example, a gNB may allocate CS resources for uplink datatransmission to a wireless device. The gNB may transmit one or more RRCmessages indicating a periodicity of the CS grant. The gNB may transmita DCI via a PDCCH addressed to a CS-RNTI activating the CS resources.The DCI may comprise parameters indicating that the uplink grant is a CSgrant. The CS grant may be implicitly reused according to theperiodicity defined by the one or more RRC message, until deactivated.

In an example, a base station may transmit DCI/control signaling viaPDCCH. The DCI may take a format in a plurality of formats. A DCI maycomprise downlink and/or uplink scheduling information (e.g., resourceallocation information, HARQ related parameters, MCS), request for CSI(e.g., aperiodic CQI reports), request for SRS, uplink power controlcommands for one or more cells, one or more timing information (e.g., TBtransmission/reception timing, HARQ feedback timing, etc.), etc. In anexample, a DCI may indicate an uplink grant comprising transmissionparameters for one or more transport blocks. In an example, a DCI mayindicate downlink assignment indicating parameters for receiving one ormore transport blocks. In an example, a DCI may be used by base stationto initiate a contention-free random access at the wireless device. Inan example, the base station may transmit a DCI comprising slot formatindicator (SFI) notifying a slot format. In an example, the base stationmay transmit a DCI comprising pre-emption indication notifying thePRB(s) and/or OFDM symbol(s) where a UE may assume no transmission isintended for the UE. In an example, the base station may transmit a DCIfor group power control of PUCCH or PUSCH or SRS. In an example, a DCImay correspond to an RNTI. In an example, the wireless device may obtainan RNTI in response to completing the initial access (e.g., C-RNTI). Inan example, the base station may configure an RNTI for the wireless(e.g., CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI,TPC-SRS-RNTI). In an example, the wireless device may compute an RNTI(e.g., the wireless device may compute RA-RNTI based on resources usedfor transmission of a preamble). In an example, an RNTI may have apre-configured value (e.g., P-RNTI or SI-RNTI). In an example, awireless device may monitor a group common search space which may beused by base station for transmitting DCIs that are intended for a groupof UEs. In an example, a group common DCI may correspond to an RNTIwhich is commonly configured for a group of UEs. In an example, awireless device may monitor a UE-specific search space. In an example, aUE specific DCI may correspond to an RNTI configured for the wirelessdevice.

A NR system may support a single beam operation and/or a multi-beamoperation. In a multi-beam operation, a base station may perform adownlink beam sweeping to provide coverage for common control channelsand/or downlink SS blocks, which may comprise at least a PSS, a SSS,and/or PBCH. A wireless device may measure quality of a beam pair linkusing one or more RSs. One or more SS blocks, or one or more CSI-RSresources, associated with a CSI-RS resource index (CRI), or one or moreDM-RSs of PBCH, may be used as RS for measuring quality of a beam pairlink. Quality of a beam pair link may be defined as a reference signalreceived power (RSRP) value, or a reference signal received quality(RSRQ) value, and/or a CSI value measured on RS resources. The basestation may indicate whether an RS resource, used for measuring a beampair link quality, is quasi-co-located (QCLed) with DM-RSs of a controlchannel. A RS resource and DM-RSs of a control channel may be calledQCLed when a channel characteristics from a transmission on an RS to awireless device, and that from a transmission on a control channel to awireless device, are similar or same under a configured criterion. In amulti-beam operation, a wireless device may perform an uplink beamsweeping to access a cell.

In an example, a wireless device may be configured to monitor PDCCH onone or more beam pair links simultaneously depending on a capability ofa wireless device. This may increase robustness against beam pair linkblocking. A base station may transmit one or more messages to configurea wireless device to monitor PDCCH on one or more beam pair links indifferent PDCCH OFDM symbols. For example, a base station may transmithigher layer signaling (e.g. RRC signaling) or MAC CE comprisingparameters related to the Rx beam setting of a wireless device formonitoring PDCCH on one or more beam pair links. A base station maytransmit indication of spatial QCL assumption between an DL RS antennaport(s) (for example, cell-specific CSI-RS, or wireless device-specificCSI-RS, or SS block, or PBCH with or without DM-RSs of PBCH), and DL RSantenna port(s) for demodulation of DL control channel Signaling forbeam indication for a PDCCH may be MAC CE signaling, or RRC signaling,or DCI signaling, or specification-transparent and/or implicit method,and combination of these signaling methods.

For reception of unicast DL data channel, a base station may indicatespatial QCL parameters between DL RS antenna port(s) and DM-RS antennaport(s) of DL data channel. The base station may transmit DCI (e.g.downlink grants) comprising information indicating the RS antennaport(s). The information may indicate RS antenna port(s) which may beQCL-ed with the DM-RS antenna port(s). Different set of DM-RS antennaport(s) for a DL data channel may be indicated as QCL with different setof the RS antenna port(s).

FIG. 9A is an example of beam sweeping in a DL channel. In anRRC_INACTIVE state or RRC_IDLE state, a wireless device may assume thatSS blocks form an SS burst 940, and an SS burst set 950. The SS burstset 950 may have a given periodicity. For example, in a multi-beamoperation, a base station 120 may transmit SS blocks in multiple beams,together forming a SS burst 940. One or more SS blocks may betransmitted on one beam. If multiple SS bursts 940 are transmitted withmultiple beams, SS bursts together may form SS burst set 950.

A wireless device may further use CSI-RS in the multi-beam operation forestimating a beam quality of a links between a wireless device and abase station. A beam may be associated with a CSI-RS. For example, awireless device may, based on a RSRP measurement on CSI-RS, report abeam index, as indicated in a CRI for downlink beam selection, andassociated with a RSRP value of a beam. A CSI-RS may be transmitted on aCSI-RS resource including at least one of one or more antenna ports, oneor more time or frequency radio resources. A CSI-RS resource may beconfigured in a cell-specific way by common RRC signaling, or in awireless device-specific way by dedicated RRC signaling, and/or L1/L2signaling. Multiple wireless devices covered by a cell may measure acell-specific CSI-RS resource. A dedicated subset of wireless devicescovered by a cell may measure a wireless device-specific CSI-RSresource.

A CSI-RS resource may be transmitted periodically, or using aperiodictransmission, or using a multi-shot or semi-persistent transmission. Forexample, in a periodic transmission in FIG. 9A, a base station 120 maytransmit configured CSI-RS resources 940 periodically using a configuredperiodicity in a time domain. In an aperiodic transmission, a configuredCSI-RS resource may be transmitted in a dedicated time slot. In amulti-shot or semi-persistent transmission, a configured CSI-RS resourcemay be transmitted within a configured period. Beams used for CSI-RStransmission may have different beam width than beams used for SS-blockstransmission.

FIG. 9B is an example of a beam management procedure in an example newradio network. A base station 120 and/or a wireless device 110 mayperform a downlink L1/L2 beam management procedure. One or more of thefollowing downlink L1/L2 beam management procedures may be performedwithin one or more wireless devices 110 and one or more base stations120. In an example, a P-1 procedure 910 may be used to enable thewireless device 110 to measure one or more Transmission (Tx) beamsassociated with the base station 120 to support a selection of a firstset of Tx beams associated with the base station 120 and a first set ofRx beam(s) associated with a wireless device 110. For beamforming at abase station 120, a base station 120 may sweep a set of different TXbeams. For beamforming at a wireless device 110, a wireless device 110may sweep a set of different Rx beams. In an example, a P-2 procedure920 may be used to enable a wireless device 110 to measure one or moreTx beams associated with a base station 120 to possibly change a firstset of Tx beams associated with a base station 120. A P-2 procedure 920may be performed on a possibly smaller set of beams for beam refinementthan in the P-1 procedure 910. A P-2 procedure 920 may be a special caseof a P-1 procedure 910. In an example, a P-3 procedure 930 may be usedto enable a wireless device 110 to measure at least one Tx beamassociated with a base station 120 to change a first set of Rx beamsassociated with a wireless device 110.

A wireless device 110 may transmit one or more beam management reportsto a base station 120. In one or more beam management reports, awireless device 110 may indicate some beam pair quality parameters,comprising at least, one or more beam identifications; RSRP; PrecodingMatrix Indicator (PMI)/Channel Quality Indicator (CQI)/Rank Indicator(RI) of a subset of configured beams. Based on one or more beammanagement reports, a base station 120 may transmit to a wireless device110 a signal indicating that one or more beam pair links are one or moreserving beams. A base station 120 may transmit PDCCH and PDSCH for awireless device 110 using one or more serving beams.

In an example embodiment, new radio network may support a BandwidthAdaptation (BA). In an example, receive and/or transmit bandwidthsconfigured by an UE employing a BA may not be large. For example, areceive and/or transmit bandwidths may not be as large as a bandwidth ofa cell. Receive and/or transmit bandwidths may be adjustable. Forexample, a UE may change receive and/or transmit bandwidths, e.g., toshrink during period of low activity to save power. For example, a UEmay change a location of receive and/or transmit bandwidths in afrequency domain, e.g. to increase scheduling flexibility. For example,a UE may change a subcarrier spacing, e.g. to allow different services.

In an example embodiment, a subset of a total cell bandwidth of a cellmay be referred to as a Bandwidth Part (BWP). A base station mayconfigure a UE with one or more BWPs to achieve a BA. For example, abase station may indicate, to a UE, which of the one or more(configured) BWPs is an active BWP.

FIG. 10 is an example diagram of 3 BWPs configured: BWP1 (1010 and 1050)with a width of 40 MHz and subcarrier spacing of 15 kHz; BWP2 (1020 and1040) with a width of 10 MHz and subcarrier spacing of 15 kHz; BWP3 1030with a width of 20 MHz and subcarrier spacing of 60 kHz.

In an example, a UE, configured for operation in one or more BWPs of acell, may be configured by one or more higher layers (e.g. RRC layer)for a cell a set of one or more BWPs (e.g., at most four BWPs) forreceptions by the UE (DL BWP set) in a DL bandwidth by at least oneparameter DL-BWP and a set of one or more BWPs (e.g., at most four BWPs)for transmissions by a UE (UL BWP set) in an UL bandwidth by at leastone parameter UL-BWP for a cell.

To enable BA on the PCell, a base station may configure a UE with one ormore UL and DL BWP pairs. To enable BA on SCells (e.g., in case of CA),a base station may configure a UE at least with one or more DL BWPs(e.g., there may be none in an UL).

In an example, an initial active DL BWP may be defined by at least oneof a location and number of contiguous PRBs, a subcarrier spacing, or acyclic prefix, for a control resource set for at least one common searchspace. For operation on the PCell, one or more higher layer parametersmay indicate at least one initial UL BWP for a random access procedure.If a UE is configured with a secondary carrier on a primary cell, the UEmay be configured with an initial BWP for random access procedure on asecondary carrier.

In an example, for unpaired spectrum operation, a UE may expect that acenter frequency for a DL BWP may be same as a center frequency for a ULBWP.

For example, for a DL BWP or an UL BWP in a set of one or more DL BWPsor one or more UL BWPs, respectively, a base statin may semi-staticallyconfigure a UE for a cell with one or more parameters indicating atleast one of following: a subcarrier spacing; a cyclic prefix; a numberof contiguous PRBs; an index in the set of one or more DL BWPs and/orone or more UL BWPs; a link between a DL BWP and an UL BWP from a set ofconfigured DL BWPs and UL BWPs; a DCI detection to a PDSCH receptiontiming; a PDSCH reception to a HARQ-ACK transmission timing value; a DCIdetection to a PUSCH transmission timing value; an offset of a first PRBof a DL bandwidth or an UL bandwidth, respectively, relative to a firstPRB of a bandwidth.

In an example, for a DL BWP in a set of one or more DL BWPs on a PCell,a base station may configure a UE with one or more control resource setsfor at least one type of common search space and/or one UE-specificsearch space. For example, a base station may not configure a UE withouta common search space on a PCell, or on a PSCell, in an active DL BWP.

For an UL BWP in a set of one or more UL BWPs, a base station mayconfigure a UE with one or more resource sets for one or more PUCCHtransmissions.

In an example, if a DCI comprises a BWP indicator field, a BWP indicatorfield value may indicate an active DL BWP, from a configured DL BWP set,for one or more DL receptions. If a DCI comprises a BWP indicator field,a BWP indicator field value may indicate an active UL BWP, from aconfigured UL BWP set, for one or more UL transmissions.

In an example, for a PCell, a base station may semi-statically configurea UE with a default DL BWP among configured DL BWPs. If a UE is notprovided a default DL BWP, a default BWP may be an initial active DLBWP.

In an example, a base station may configure a UE with a timer value fora PCell. For example, a UE may start a timer, referred to as BWPinactivity timer, when a UE detects a DCI indicating an active DL BWP,other than a default DL BWP, for a paired spectrum operation or when aUE detects a DCI indicating an active DL BWP or UL BWP, other than adefault DL BWP or UL BWP, for an unpaired spectrum operation. The UE mayincrement the timer by an interval of a first value (e.g., the firstvalue may be 1 millisecond or 0.5 milliseconds) if the UE does notdetect a DCI during the interval for a paired spectrum operation or foran unpaired spectrum operation. In an example, the timer may expire whenthe timer is equal to the timer value. A UE may switch to the default DLBWP from an active DL BWP when the timer expires.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of BWP inactivity timer(for example, the second BWP may be a default BWP). For example, FIG. 10is an example diagram of 3 BWPs configured, BWP1 (1010 and 1050), BWP2(1020 and 1040), and BWP3 (1030). BWP2 (1020 and 1040) may be a defaultBWP. BWP1 (1010) may be an initial active BWP. In an example, a UE mayswitch an active BWP from BWP1 1010 to BWP2 1020 in response to anexpiry of BWP inactivity timer. For example, a UE may switch an activeBWP from BWP2 1020 to BWP3 1030 in response to receiving a DCIindicating BWP3 1030 as an active BWP. Switching an active BWP from BWP31030 to BWP2 1040 and/or from BWP2 1040 to BWP1 1050 may be in responseto receiving a DCI indicating an active BWP and/or in response to anexpiry of BWP inactivity timer.

In an example, if a UE is configured for a secondary cell with a defaultDL BWP among configured DL BWPs and a timer value, UE procedures on asecondary cell may be same as on a primary cell using the timer valuefor the secondary cell and the default DL BWP for the secondary cell.

In an example, if a base station configures a UE with a first active DLBWP and a first active UL BWP on a secondary cell or carrier, a UE mayemploy an indicated DL BWP and an indicated UL BWP on a secondary cellas a respective first active DL BWP and first active UL BWP on asecondary cell or carrier.

FIG. 11A and FIG. 11B show packet flows employing a multi connectivity(e.g. dual connectivity, multi connectivity, tight interworking, and/orthe like). FIG. 11A is an example diagram of a protocol structure of awireless device 110 (e.g. UE) with CA and/or multi connectivity as peran aspect of an embodiment. FIG. 11B is an example diagram of a protocolstructure of multiple base stations with CA and/or multi connectivity asper an aspect of an embodiment. The multiple base stations may comprisea master node, MN 1130 (e.g. a master node, a master base station, amaster gNB, a master eNB, and/or the like) and a secondary node, SN 1150(e.g. a secondary node, a secondary base station, a secondary gNB, asecondary eNB, and/or the like). A master node 1130 and a secondary node1150 may co-work to communicate with a wireless device 110.

When multi connectivity is configured for a wireless device 110, thewireless device 110, which may support multiple reception/transmissionfunctions in an RRC connected state, may be configured to utilize radioresources provided by multiple schedulers of a multiple base stations.Multiple base stations may be inter-connected via a non-ideal or idealbackhaul (e.g. Xn interface, X2 interface, and/or the like). A basestation involved in multi connectivity for a certain wireless device mayperform at least one of two different roles: a base station may eitheract as a master base station or as a secondary base station. In multiconnectivity, a wireless device may be connected to one master basestation and one or more secondary base stations. In an example, a masterbase station (e.g. the MN 1130) may provide a master cell group (MCG)comprising a primary cell and/or one or more secondary cells for awireless device (e.g. the wireless device 110). A secondary base station(e.g. the SN 1150) may provide a secondary cell group (SCG) comprising aprimary secondary cell (PSCell) and/or one or more secondary cells for awireless device (e.g. the wireless device 110).

In multi connectivity, a radio protocol architecture that a beareremploys may depend on how a bearer is setup. In an example, threedifferent type of bearer setup options may be supported: an MCG bearer,an SCG bearer, and/or a split bearer. A wireless device mayreceive/transmit packets of an MCG bearer via one or more cells of theMCG, and/or may receive/transmits packets of an SCG bearer via one ormore cells of an SCG. Multi-connectivity may also be described as havingat least one bearer configured to use radio resources provided by thesecondary base station. Multi-connectivity may or may not beconfigured/implemented in some of the example embodiments.

In an example, a wireless device (e.g. Wireless Device 110) may transmitand/or receive: packets of an MCG bearer via an SDAP layer (e.g. SDAP1110), a PDCP layer (e.g. NR PDCP 1111), an RLC layer (e.g. MN RLC1114), and a MAC layer (e.g. MN MAC 1118); packets of a split bearer viaan SDAP layer (e.g. SDAP 1110), a PDCP layer (e.g. NR PDCP 1112), one ofa master or secondary RLC layer (e.g. MN RLC 1115, SN RLC 1116), and oneof a master or secondary MAC layer (e.g. MN MAC 1118, SN MAC 1119);and/or packets of an SCG bearer via an SDAP layer (e.g. SDAP 1110), aPDCP layer (e.g. NR PDCP 1113), an RLC layer (e.g. SN RLC 1117), and aMAC layer (e.g. MN MAC 1119).

In an example, a master base station (e.g. MN 1130) and/or a secondarybase station (e.g. SN 1150) may transmit/receive: packets of an MCGbearer via a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g. NR PDCP 1121, NR PDCP1142), a master node RLC layer (e.g. MN RLC 1124, MN RLC 1125), and amaster node MAC layer (e.g. MN MAC 1128); packets of an SCG bearer via amaster or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), amaster or secondary node PDCP layer (e.g. NR PDCP 1122, NR PDCP 1143), asecondary node RLC layer (e.g. SN RLC 1146, SN RLC 1147), and asecondary node MAC layer (e.g. SN MAC 1148); packets of a split bearervia a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), amaster or secondary node PDCP layer (e.g. NR PDCP 1123, NR PDCP 1141), amaster or secondary node RLC layer (e.g. MN RLC 1126, SN RLC 1144, SNRLC 1145, MN RLC 1127), and a master or secondary node MAC layer (e.g.MN MAC 1128, SN MAC 1148).

In multi connectivity, a wireless device may configure multiple MACentities: one MAC entity (e.g. MN MAC 1118) for a master base station,and other MAC entities (e.g. SN MAC 1119) for a secondary base station.In multi-connectivity, a configured set of serving cells for a wirelessdevice may comprise two subsets: an MCG comprising serving cells of amaster base station, and SCGs comprising serving cells of a secondarybase station. For an SCG, one or more of following configurations may beapplied: at least one cell of an SCG has a configured UL CC and at leastone cell of a SCG, named as primary secondary cell (PSCell, PCell ofSCG, or sometimes called PCell), is configured with PUCCH resources;when an SCG is configured, there may be at least one SCG bearer or oneSplit bearer; upon detection of a physical layer problem or a randomaccess problem on a PSCell, or a number of NR RLC retransmissions hasbeen reached associated with the SCG, or upon detection of an accessproblem on a PSCell during a SCG addition or a SCG change: an RRCconnection re-establishment procedure may not be triggered, ULtransmissions towards cells of an SCG may be stopped, a master basestation may be informed by a wireless device of a SCG failure type, forsplit bearer, a DL data transfer over a master base station may bemaintained; an NR RLC acknowledged mode (AM) bearer may be configuredfor a split bearer; PCell and/or PSCell may not be de-activated; PSCellmay be changed with a SCG change procedure (e.g. with security keychange and a RACH procedure); and/or a bearer type change between asplit bearer and a SCG bearer or simultaneous configuration of a SCG anda split bearer may or may not supported.

With respect to interaction between a master base station and asecondary base stations for multi-connectivity, one or more of thefollowing may be applied: a master base station and/or a secondary basestation may maintain RRM measurement configurations of a wirelessdevice; a master base station may (e.g. based on received measurementreports, traffic conditions, and/or bearer types) may decide to requesta secondary base station to provide additional resources (e.g. servingcells) for a wireless device; upon receiving a request from a masterbase station, a secondary base station may create/modify a containerthat may result in configuration of additional serving cells for awireless device (or decide that the secondary base station has noresource available to do so); for a UE capability coordination, a masterbase station may provide (a part of) an AS configuration and UEcapabilities to a secondary base station; a master base station and asecondary base station may exchange information about a UE configurationby employing of RRC containers (inter-node messages) carried via Xnmessages; a secondary base station may initiate a reconfiguration of thesecondary base station existing serving cells (e.g. PUCCH towards thesecondary base station); a secondary base station may decide which cellis a PSCell within a SCG; a master base station may or may not changecontent of RRC configurations provided by a secondary base station; incase of a SCG addition and/or a SCG SCell addition, a master basestation may provide recent (or the latest) measurement results for SCGcell(s); a master base station and secondary base stations may receiveinformation of SFN and/or subframe offset of each other from OAM and/orvia an Xn interface, (e.g. for a purpose of DRX alignment and/oridentification of a measurement gap). In an example, when adding a newSCG SCell, dedicated RRC signaling may be used for sending requiredsystem information of a cell as for CA, except for a SFN acquired from aMIB of a PSCell of a SCG.

FIG. 12 is an example diagram of a random access procedure. One or moreevents may trigger a random access procedure. For example, one or moreevents may be at least one of following: initial access from RRC_IDLE,RRC connection re-establishment procedure, handover, DL or UL dataarrival during RRC_CONNECTED when UL synchronization status isnon-synchronised, transition from RRC_Inactive, and/or request for othersystem information. For example, a PDCCH order, a MAC entity, and/or abeam failure indication may initiate a random access procedure.

In an example embodiment, a random access procedure may be at least oneof a contention based random access procedure and a contention freerandom access procedure. For example, a contention based random accessprocedure may comprise, one or more Msg 1 1220 transmissions, one ormore Msg2 1230 transmissions, one or more Msg3 1240 transmissions, andcontention resolution 1250. For example, a contention free random accessprocedure may comprise one or more Msg 1 1220 transmissions and one ormore Msg2 1230 transmissions.

In an example, a base station may transmit (e.g., unicast, multicast, orbroadcast), to a UE, a RACH configuration 1210 via one or more beams.The RACH configuration 1210 may comprise one or more parametersindicating at least one of following: available set of PRACH resourcesfor a transmission of a random access preamble, initial preamble power(e.g., random access preamble initial received target power), an RSRPthreshold for a selection of a SS block and corresponding PRACHresource, a power-ramping factor (e.g., random access preamble powerramping step), random access preamble index, a maximum number ofpreamble transmission, preamble group A and group B, a threshold (e.g.,message size) to determine the groups of random access preambles, a setof one or more random access preambles for system information requestand corresponding PRACH resource(s), if any, a set of one or more randomaccess preambles for beam failure recovery request and correspondingPRACH resource(s), if any, a time window to monitor RA response(s), atime window to monitor response(s) on beam failure recovery request,and/or a contention resolution timer.

In an example, the Msg1 1220 may be one or more transmissions of arandom access preamble. For a contention based random access procedure,a UE may select a SS block with a RSRP above the RSRP threshold. Ifrandom access preambles group B exists, a UE may select one or morerandom access preambles from a group A or a group B depending on apotential Msg3 1240 size. If a random access preambles group B does notexist, a UE may select the one or more random access preambles from agroup A. A UE may select a random access preamble index randomly (e.g.with equal probability or a normal distribution) from one or more randomaccess preambles associated with a selected group. If a base stationsemi-statically configures a UE with an association between randomaccess preambles and SS blocks, the UE may select a random accesspreamble index randomly with equal probability from one or more randomaccess preambles associated with a selected SS block and a selectedgroup.

For example, a UE may initiate a contention free random access procedurebased on a beam failure indication from a lower layer. For example, abase station may semi-statically configure a UE with one or morecontention free PRACH resources for beam failure recovery requestassociated with at least one of SS blocks and/or CSI-RSs. If at leastone of SS blocks with a RSRP above a first RSRP threshold amongstassociated SS blocks or at least one of CSI-RSs with a RSRP above asecond RSRP threshold amongst associated CSI-RSs is available, a UE mayselect a random access preamble index corresponding to a selected SSblock or CSI-RS from a set of one or more random access preambles forbeam failure recovery request.

For example, a UE may receive, from a base station, a random accesspreamble index via PDCCH or RRC for a contention free random accessprocedure. If a base station does not configure a UE with at least onecontention free PRACH resource associated with SS blocks or CSI-RS, theUE may select a random access preamble index. If a base stationconfigures a UE with one or more contention free PRACH resourcesassociated with SS blocks and at least one SS block with a RSRP above afirst RSRP threshold amongst associated SS blocks is available, the UEmay select the at least one SS block and select a random access preamblecorresponding to the at least one SS block. If a base station configuresa UE with one or more contention free PRACH resources associated withCSI-RSs and at least one CSI-RS with a RSRP above a second RSPRthreshold amongst the associated CSI-RSs is available, the UE may selectthe at least one CSI-RS and select a random access preamblecorresponding to the at least one CSI-RS.

A UE may perform one or more Msg1 1220 transmissions by transmitting theselected random access preamble. For example, if a UE selects an SSblock and is configured with an association between one or more PRACHoccasions and one or more SS blocks, the UE may determine an PRACHoccasion from one or more PRACH occasions corresponding to a selected SSblock. For example, if a UE selects a CSI-RS and is configured with anassociation between one or more PRACH occasions and one or more CSI-RSs,the UE may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected CSI-RS. A UE may transmit, to a basestation, a selected random access preamble via a selected PRACHoccasions. A UE may determine a transmit power for a transmission of aselected random access preamble at least based on an initial preamblepower and a power-ramping factor. A UE may determine a RA-RNTIassociated with a selected PRACH occasions in which a selected randomaccess preamble is transmitted. For example, a UE may not determine aRA-RNTI for a beam failure recovery request. A UE may determine anRA-RNTI at least based on an index of a first OFDM symbol and an indexof a first slot of a selected PRACH occasions, and/or an uplink carrierindex for a transmission of Msg1 1220.

In an example, a UE may receive, from a base station, a random accessresponse, Msg 2 1230. A UE may start a time window (e.g., ra-ResponseWindow) to monitor a random access response. For beam failure recoveryrequest, a base station may configure a UE with a different time window(e.g., bfr-ResponseWindow) to monitor response on beam failure recoveryrequest. For example, a UE may start a time window (e.g.,ra-ResponseWindow or bfr-Response Window) at a start of a first PDCCHoccasion after a fixed duration of one or more symbols from an end of apreamble transmission. If a UE transmits multiple preambles, the UE maystart a time window at a start of a first PDCCH occasion after a fixedduration of one or more symbols from an end of a first preambletransmission. A UE may monitor a PDCCH of a cell for at least one randomaccess response identified by a RA-RNTI or for at least one response tobeam failure recovery request identified by a C-RNTI while a timer for atime window is running.

In an example, a UE may consider a reception of random access responsesuccessful if at least one random access response comprises a randomaccess preamble identifier corresponding to a random access preambletransmitted by the UE. A UE may consider the contention free randomaccess procedure successfully completed if a reception of random accessresponse is successful. If a contention free random access procedure istriggered for a beam failure recovery request, a UE may consider acontention free random access procedure successfully complete if a PDCCHtransmission is addressed to a C-RNTI. In an example, if at least onerandom access response comprises a random access preamble identifier, aUE may consider the random access procedure successfully completed andmay indicate a reception of an acknowledgement for a system informationrequest to upper layers. If a UE has signaled multiple preambletransmissions, the UE may stop transmitting remaining preambles (if any)in response to a successful reception of a corresponding random accessresponse.

In an example, a UE may perform one or more Msg 3 1240 transmissions inresponse to a successful reception of random access response (e.g., fora contention based random access procedure). A UE may adjust an uplinktransmission timing based on a timing advanced command indicated by arandom access response and may transmit one or more transport blocksbased on an uplink grant indicated by a random access response.Subcarrier spacing for PUSCH transmission for Msg3 1240 may be providedby at least one higher layer (e.g. RRC) parameter. A UE may transmit arandom access preamble via PRACH and Msg3 1240 via PUSCH on a same cell.A base station may indicate an UL BWP for a PUSCH transmission of Msg31240 via system information block. A UE may employ HARQ for aretransmission of Msg 3 1240.

In an example, multiple UEs may perform Msg 1 1220 by transmitting asame preamble to a base station and receive, from the base station, asame random access response comprising an identity (e.g., TC-RNTI).Contention resolution 1250 may ensure that a UE does not incorrectly usean identity of another UE. For example, contention resolution 1250 maybe based on C-RNTI on PDCCH or a UE contention resolution identity onDL-SCH. For example, if a base station assigns a C-RNTI to a UE, the UEmay perform contention resolution 1250 based on a reception of a PDCCHtransmission that is addressed to the C-RNTI. In response to detectionof a C-RNTI on a PDCCH, a UE may consider contention resolution 1250successful and may consider a random access procedure successfullycompleted. If a UE has no valid C-RNTI, a contention resolution may beaddressed by employing a TC-RNTI. For example, if a MAC PDU issuccessfully decoded and a MAC PDU comprises a UE contention resolutionidentity MAC CE that matches the CCCH SDU transmitted in Msg3 1250, a UEmay consider the contention resolution 1250 successful and may considerthe random access procedure successfully completed.

FIG. 13 is an example structure for MAC entities as per an aspect of anembodiment. In an example, a wireless device may be configured tooperate in a multi-connectivity mode. A wireless device in RRC_CONNECTEDwith multiple RX/TX may be configured to utilize radio resourcesprovided by multiple schedulers located in a plurality of base stations.The plurality of base stations may be connected via a non-ideal or idealbackhaul over the Xn interface. In an example, a base station in aplurality of base stations may act as a master base station or as asecondary base station. A wireless device may be connected to one masterbase station and one or more secondary base stations. A wireless devicemay be configured with multiple MAC entities, e.g. one MAC entity formaster base station, and one or more other MAC entities for secondarybase station(s). In an example, a configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and one or more SCGs comprising servingcells of a secondary base station(s). FIG. 13 illustrates an examplestructure for MAC entities when MCG and SCG are configured for awireless device.

In an example, at least one cell in a SCG may have a configured UL CC,wherein a cell of at least one cell may be called PSCell or PCell ofSCG, or sometimes may be simply called PCell. A PSCell may be configuredwith PUCCH resources. In an example, when a SCG is configured, there maybe at least one SCG bearer or one split bearer. In an example, upondetection of a physical layer problem or a random access problem on aPSCell, or upon reaching a number of RLC retransmissions associated withthe SCG, or upon detection of an access problem on a PSCell during a SCGaddition or a SCG change: an RRC connection re-establishment proceduremay not be triggered, UL transmissions towards cells of an SCG may bestopped, a master base station may be informed by a UE of a SCG failuretype and DL data transfer over a master base station may be maintained.

In an example, a MAC sublayer may provide services such as data transferand radio resource allocation to upper layers (e.g. 1310 or 1320). A MACsublayer may comprise a plurality of MAC entities (e.g. 1350 and 1360).A MAC sublayer may provide data transfer services on logical channels.To accommodate different kinds of data transfer services, multiple typesof logical channels may be defined. A logical channel may supporttransfer of a particular type of information. A logical channel type maybe defined by what type of information (e.g., control or data) istransferred. For example, BCCH, PCCH, CCCH and DCCH may be controlchannels and DTCH may be a traffic channel. In an example, a first MACentity (e.g. 1310) may provide services on PCCH, BCCH, CCCH, DCCH, DTCHand MAC control elements. In an example, a second MAC entity (e.g. 1320)may provide services on BCCH, DCCH, DTCH and MAC control elements.

A MAC sublayer may expect from a physical layer (e.g. 1330 or 1340)services such as data transfer services, signaling of HARQ feedback,signaling of scheduling request or measurements (e.g. CQI). In anexample, in dual connectivity, two MAC entities may be configured for awireless device: one for MCG and one for SCG. A MAC entity of wirelessdevice may handle a plurality of transport channels. In an example, afirst MAC entity may handle first transport channels comprising a PCCHof MCG, a first BCH of MCG, one or more first DL-SCHs of MCG, one ormore first UL-SCHs of MCG and one or more first RACHs of MCG. In anexample, a second MAC entity may handle second transport channelscomprising a second BCH of SCG, one or more second DL-SCHs of SCG, oneor more second UL-SCHs of SCG and one or more second RACHs of SCG.

In an example, if a MAC entity is configured with one or more SCells,there may be multiple DL-SCHs and there may be multiple UL-SCHs as wellas multiple RACHs per MAC entity. In an example, there may be one DL-SCHand UL-SCH on a SpCell. In an example, there may be one DL-SCH, zero orone UL-SCH and zero or one RACH for an SCell. A DL-SCH may supportreceptions using different numerologies and/or TTI duration within a MACentity. A UL-SCH may also support transmissions using differentnumerologies and/or TTI duration within the MAC entity.

In an example, a MAC sublayer may support different functions and maycontrol these functions with a control (e.g. 1355 or 1365) element.Functions performed by a MAC entity may comprise mapping between logicalchannels and transport channels (e.g., in uplink or downlink),multiplexing (e.g. 1352 or 1362) of MAC SDUs from one or differentlogical channels onto transport blocks (TB) to be delivered to thephysical layer on transport channels (e.g., in uplink), demultiplexing(e.g. 1352 or 1362) of MAC SDUs to one or different logical channelsfrom transport blocks (TB) delivered from the physical layer ontransport channels (e.g., in downlink), scheduling information reporting(e.g., in uplink), error correction through HARQ in uplink or downlink(e.g. 1363), and logical channel prioritization in uplink (e.g. 1351 or1361). A MAC entity may handle a random access process (e.g. 1354 or1364).

FIG. 14 is an example diagram of a RAN architecture comprising one ormore base stations. In an example, a protocol stack (e.g. RRC, SDAP,PDCP, RLC, MAC, and PHY) may be supported at a node. A base station(e.g. gNB 120A or 120B) may comprise a base station central unit (CU)(e.g. gNB-CU 1420A or 1420B) and at least one base station distributedunit (DU) (e.g. gNB-DU 1430A, 1430B, 1430C, or 1430D) if a functionalsplit is configured. Upper protocol layers of a base station may belocated in a base station CU, and lower layers of the base station maybe located in the base station DUs. An F1 interface (e.g. CU-DUinterface) connecting a base station CU and base station DUs may be anideal or non-ideal backhaul. F1-C may provide a control plane connectionover an F1 interface, and F1-U may provide a user plane connection overthe F1 interface. In an example, an Xn interface may be configuredbetween base station CUs.

In an example, a base station CU may comprise an RRC function, an SDAPlayer, and a PDCP layer, and base station DUs may comprise an RLC layer,a MAC layer, and a PHY layer. In an example, various functional splitoptions between a base station CU and base station DUs may be possibleby locating different combinations of upper protocol layers (RANfunctions) in a base station CU and different combinations of lowerprotocol layers (RAN functions) in base station DUs. A functional splitmay support flexibility to move protocol layers between a base stationCU and base station DUs depending on service requirements and/or networkenvironments.

In an example, functional split options may be configured per basestation, per base station CU, per base station DU, per UE, per bearer,per slice, or with other granularities. In per base station CU split, abase station CU may have a fixed split option, and base station DUs maybe configured to match a split option of a base station CU. In per basestation DU split, a base station DU may be configured with a differentsplit option, and a base station CU may provide different split optionsfor different base station DUs. In per UE split, a base station (basestation CU and at least one base station DUs) may provide differentsplit options for different wireless devices. In per bearer split,different split options may be utilized for different bearers. In perslice splice, different split options may be applied for differentslices.

FIG. 15 is an example diagram showing RRC state transitions of awireless device. In an example, a wireless device may be in at least oneRRC state among an RRC connected state (e.g. RRC Connected 1530,RRC_Connected), an RRC idle state (e.g. RRC Idle 1510, RRC_Idle), and/oran RRC inactive state (e.g. RRC Inactive 1520, RRC_Inactive). In anexample, in an RRC connected state, a wireless device may have at leastone RRC connection with at least one base station (e.g. gNB and/or eNB),which may have a UE context of the wireless device. A UE context (e.g. awireless device context) may comprise at least one of an access stratumcontext, one or more radio link configuration parameters, bearer (e.g.data radio bearer (DRB), signaling radio bearer (SRB), logical channel,QoS flow, PDU session, and/or the like) configuration information,security information, PHY/MAC/RLC/PDCP/SDAP layer configurationinformation, and/or the like configuration information for a wirelessdevice. In an example, in an RRC idle state, a wireless device may nothave an RRC connection with a base station, and a UE context of awireless device may not be stored in a base station. In an example, inan RRC inactive state, a wireless device may not have an RRC connectionwith a base station. A UE context of a wireless device may be stored ina base station, which may be called as an anchor base station (e.g. lastserving base station).

In an example, a wireless device may transition a UE RRC state betweenan RRC idle state and an RRC connected state in both ways (e.g.connection release 1540 or connection establishment 1550; or connectionreestablishment) and/or between an RRC inactive state and an RRCconnected state in both ways (e.g. connection inactivation 1570 orconnection resume 1580). In an example, a wireless device may transitionits RRC state from an RRC inactive state to an RRC idle state (e.g.connection release 1560).

In an example, an anchor base station may be a base station that maykeep a UE context (a wireless device context) of a wireless device atleast during a time period that a wireless device stays in a RANnotification area (RNA) of an anchor base station, and/or that awireless device stays in an RRC inactive state. In an example, an anchorbase station may be a base station that a wireless device in an RRCinactive state was lastly connected to in a latest RRC connected stateor that a wireless device lastly performed an RNA update procedure in.In an example, an RNA may comprise one or more cells operated by one ormore base stations. In an example, a base station may belong to one ormore RNAs. In an example, a cell may belong to one or more RNAs.

In an example, a wireless device may transition a UE RRC state from anRRC connected state to an RRC inactive state in a base station. Awireless device may receive RNA information from the base station. RNAinformation may comprise at least one of an RNA identifier, one or morecell identifiers of one or more cells of an RNA, a base stationidentifier, an IP address of the base station, an AS context identifierof the wireless device, a resume identifier, and/or the like.

In an example, an anchor base station may broadcast a message (e.g. RANpaging message) to base stations of an RNA to reach to a wireless devicein an RRC inactive state, and/or the base stations receiving the messagefrom the anchor base station may broadcast and/or multicast anothermessage (e.g. paging message) to wireless devices in their coveragearea, cell coverage area, and/or beam coverage area associated with theRNA through an air interface.

In an example, when a wireless device in an RRC inactive state movesinto a new RNA, the wireless device may perform an RNA update (RNAU)procedure, which may comprise a random access procedure by the wirelessdevice and/or a UE context retrieve procedure. A UE context retrieve maycomprise: receiving, by a base station from a wireless device, a randomaccess preamble; and fetching, by a base station, a UE context of thewireless device from an old anchor base station. Fetching may comprise:sending a retrieve UE context request message comprising a resumeidentifier to the old anchor base station and receiving a retrieve UEcontext response message comprising the UE context of the wirelessdevice from the old anchor base station.

In an example embodiment, a wireless device in an RRC inactive state mayselect a cell to camp on based on at least a on measurement results forone or more cells, a cell where a wireless device may monitor an RNApaging message and/or a core network paging message from a base station.In an example, a wireless device in an RRC inactive state may select acell to perform a random access procedure to resume an RRC connectionand/or to transmit one or more packets to a base station (e.g. to anetwork). In an example, if a cell selected belongs to a different RNAfrom an RNA for a wireless device in an RRC inactive state, the wirelessdevice may initiate a random access procedure to perform an RNA updateprocedure. In an example, if a wireless device in an RRC inactive statehas one or more packets, in a buffer, to transmit to a network, thewireless device may initiate a random access procedure to transmit oneor more packets to a base station of a cell that the wireless deviceselects. A random access procedure may be performed with two messages(e.g. 2 stage random access) and/or four messages (e.g. 4 stage randomaccess) between the wireless device and the base station.

In an example embodiment, a base station receiving one or more uplinkpackets from a wireless device in an RRC inactive state may fetch a UEcontext of a wireless device by transmitting a retrieve UE contextrequest message for the wireless device to an anchor base station of thewireless device based on at least one of an AS context identifier, anRNA identifier, a base station identifier, a resume identifier, and/or acell identifier received from the wireless device. In response tofetching a UE context, a base station may transmit a path switch requestfor a wireless device to a core network entity (e.g. AMF, MME, and/orthe like). A core network entity may update a downlink tunnel endpointidentifier for one or more bearers established for the wireless devicebetween a user plane core network entity (e.g. UPF, S-GW, and/or thelike) and a RAN node (e.g. the base station), e.g. changing a downlinktunnel endpoint identifier from an address of the anchor base station toan address of the base station.

A gNB may communicate with a wireless device via a wireless networkemploying one or more new radio technologies. The one or more radiotechnologies may comprise at least one of: multiple technologies relatedto physical layer; multiple technologies related to medium accesscontrol layer; and/or multiple technologies related to radio resourcecontrol layer. Example embodiments of enhancing the one or more radiotechnologies may improve performance of a wireless network. Exampleembodiments may increase the system throughput, or data rate oftransmission. Example embodiments may reduce battery consumption of awireless device. Example embodiments may improve latency of datatransmission between a gNB and a wireless device. Example embodimentsmay improve network coverage of a wireless network. Example embodimentsmay improve transmission efficiency of a wireless network.

In an example, a gNB may transmit a DCI via a PDCCH for at least one of:scheduling assignment/grant; slot format notification; pre-emptionindication; and/or power-control commands. The DCI may comprise at leastone of: identifier of a DCI format; downlink scheduling assignment(s);uplink scheduling grant(s); slot format indicator; pre-emptionindication; power-control for PUCCH/PUSCH; and/or power-control for SRS.

In an example, a downlink scheduling assignment DCI may compriseparameters indicating at least one of: identifier of a DCI format; PDSCHresource indication; transport format; HARQ information; controlinformation related to multiple antenna schemes; and/or a command forpower control of the PUCCH.

In an example, an uplink scheduling grant DCI may comprise parametersindicating at least one of: identifier of a DCI format; PUSCH resourceindication; transport format; HARQ related information; and/or a powercontrol command of the PUSCH.

In an example, different types of control information may correspond todifferent DCI message sizes. For example, supporting multiple beamsand/or spatial multiplexing in the spatial domain and noncontiguousallocation of RBs in the frequency domain may require a largerscheduling message in comparison with an uplink grant allowing forfrequency-contiguous allocation. DCI may be categorized into differentDCI formats, where a format corresponds to a certain message size and/orusage.

In an example, a wireless device may monitor one or more PDCCHs fordetecting one or more DCIs with one or more DCI formats, in a commonsearch space or a wireless device-specific search space. In an example,a wireless device may monitor PDCCH with a limited set of DCI formats tosave power consumption. In general, the more DCI formats to be detected,the more power consumed by the wireless device.

In an example, the information in the DCI formats for downlinkscheduling may comprise at least one of: identifier of a DCI format;carrier indicator; frequency domain resource assignment; time domainresource assignment; bandwidth part indicator; HARQ process number; oneor more MCS; one or more NDI; one or more RV; MIMO related information;Downlink assignment index (DAI); PUCCH resource indicator;PDSCH-to-HARQ_feedback timing indicator; TPC for PUCCH; SRS request; andpadding if necessary. In an example, the MIMO related information maycomprise at least one of: PMI; precoding information; transport blockswap flag; power offset between PDSCH and reference signal;reference-signal scrambling sequence; number of layers; and/or antennaports for the transmission; and/or Transmission Configuration Indication(TCI).

In an example, the information in the DCI formats used for uplinkscheduling may comprise at least one of: an identifier of a DCI format;carrier indicator; bandwidth part indication; resource allocation type;frequency domain resource assignment; time domain resource assignment;MCS; NDI; Phase rotation of the uplink DMRS; precoding information; CSIrequest; SRS request; Uplink index/DAI; TPC for PUSCH; and/or padding ifnecessary.

In an example, a gNB may perform CRC scrambling for a DCI, beforetransmitting the DCI via a PDCCH. The gNB may perform CRC scrambling bybinary addition of multiple bits of at least one wireless deviceidentifier (e.g., C-RNTI, CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI,TPC-PUSCH-RNTI, SP CSI C-RNTI, or TPC-SRS-RNTI) and the CRC bits of theDCI. The wireless device may check the CRC bits of the DCI whendetecting the DCI. The wireless device may receive the DCI when the CRCis scrambled by a sequence of bits that is the same as the at least onewireless device identifier.

In an example, in order to support wide bandwidth operation, a gNB maytransmit one or more PDCCHs in different control resource sets(coresets). A gNB may transmit one or more RRC messages comprisingconfiguration parameters of one or more coresets. A coreset may compriseat least one of: a first OFDM symbol; a number of consecutive OFDMsymbols; a set of resource blocks; and/or a CCE-to-REG mapping. In anexample, a gNB may transmit a PDCCH in a dedicated coreset for aparticular purpose, such as beam failure recovery confirmation.

In an example, a wireless device may monitor PDCCH for detecting DCI inone or more configured coresets, to reduce the power consumption.

In an example, a DCI format (e.g., DCI format 1_0) may be used for ascheduling of PDSCH in one DL cell. The DCI format for downlinkscheduling may comprise CRC bits scrambled by at least one wirelessdevice identifier (e.g., C-RNTI, CS-RNTI, or MCS-C-RNTI). Theinformation in the DCI format for downlink scheduling may comprise atleast one of: identifier of a DCI format; frequency domain resourceassignment; time domain resource assignment; VRB-to-PRB mapping;modulation and coding scheme; new data indicator; redundancy version;HARQ process number; downlink assignment index; TPC command forscheduled PUCCH; PUCCH resource indicator; and/or PDSCH-to-HARQ_feedbacktiming indicator.

In an example, a DCI format for downlink scheduling may be for randomaccess procedure initiated by a PDCCH order. For example, the CRC bitsof the DCI format for downlink scheduling may be scrambled by a firstradio network temporary identifier (e.g., C-RNTI), and the frequencydomain resource assignment field may be a first value (e.g., all ones),indicating that the DCI format is for random access procedure. Theinformation in the DCI format may then comprise at least one of:identifier for DCI format; frequency domain resource assignments; randomaccess preamble index; UL/SUL indicator; SS/PBCH index; PRACH maskindex; and/or reserved bits. The random access preamble index field mayindicate a preamble sequence to be used for the random access procedure.The SS/PBCH index field may indicate the SS/PBCH (SSB) that may be usedto determine one or more RACH occasions for the PRACH transmission. ThePRACH mask index field may indicate the one or more RACH occasionsassociated with the SS/PBCH indicated by the SS/PBCH index for PRACHtransmission.

A random access procedure may be initiated by a PDCCH order, or by a MACentity, or by RRC. There may be only one random access procedure ongoingat a time in a MAC entity. The random access procedure on an SCell mayonly be initiated by the PDCCH order with a first random access preambleindex field, wherein the first random access preamble index field maynot be all zeros. For example, when a new random access procedure istriggered while another is already ongoing in the MAC entity, it may beup to a wireless device implementation whether to continue with theongoing procedure or start with the new procedure (e.g. for SI request).

A wireless device may receive one or more RRC messages for a randomaccess procedure comprising at least one of parameters: PRACHconfiguration index (prach-ConfigurationIndex; one or more PRACHoccasions for a transmission of a random access preamble); initialrandom access preamble power (preambleReceivedTargetPower); a list ofone or more reference signals (CSI-RS and/or SSB) identifying one ormore candidate beams for recovery and/or the random access parameters(candidateBeamRSList); RSRP threshold for selection of a referencedownlink signal (e.g., SSB, and/or CSI-RS); a search space identity formonitoring a response of a beam failure recovery request; apower-ramping factor (powerRampingStep); a scaling factor for aprioritized random access procedure (scalingFactorBI); a random accesspreamble (ra-PreambleIndex); an association between the one or morePRACH occasions and the reference signal (CSI-RS and/or SSB:ra-ssb-OccasionMaskIndex/ra-OccasionList); a maximum number of randomaccess preamble transmission (reambleTransMax); and/or a first number ofSSBs mapped to each one of the one or more PRACH occasions and a secondnumber of contention-based random access preambles mapped to each one ofthe one or more SSBs (ssb-perRACH-OccasionAndCB-PreamblesPerSSB). Atleast one of the following wireless device variables may be used for therandom access procedure: preamble index (PREAMBLE_INDEX); preambletransmission counter (PREAMBLE_TRANSMISSION_COUNTER); transmission powerramping counter (PREAMBLE_POWER_RAMPING_COUNTER); preamble power rampingstep (PREAMBLE_POWER_RAMPING_STEP); preamble received target power(PREAMBLE_RECEIVED_TARGET_POWER); preamble backoff (PREAMBLE_BACKOFF);maximum transmission power (PCMAX); scaling factor for backoff indicator(SCALING_FACTOR_BI); and/or temporary identifier (TC-RNTI).

In an example, a random access procedure may be initiated on a servingcell. A MAC entity of a wireless device may initialize one or morerandom access parameters. The wireless device may then perform a randomaccess resource selection procedure.

In an example, a random access procedure may be initiated by a PDCCHorder. The PDCCH order may comprise a random access preamble index. Thewireless device may set the preamble index to the random access preambleindex signaled by the PDCCH order. The wireless device may select an SSBsignaled by the PDCCH order.

In an example, a contention-free random access procedure may beinitiated, wherein a wireless device receives one or more messagescomprising parameters of contention-free random access resources. Thecontention-free random access resources may be associated with one ormore reference signals (CSI-RS and/or SSB), wherein at least onereference signal of the one or more reference signals may have RSRPabove a threshold. The wireless device may select a reference signal(CSI-RS and/or SSB) amongst the at least one reference signals with RSRPabove the threshold. The wireless device may set a preamble index to arandom access preamble index corresponding to the reference signal(CSI-RS and/or SSB).

In an example, a contention-based random access procedure may beinitiated, wherein a wireless device receives one or more messagescomprising parameters of contention-based random access resources. Thewireless device may select an SSB from one or more SSBs, wherein the oneor more SSBs have RSRP above a threshold, or may select any SSB. Thewireless device may select a random access preamble, for examplerandomly with equal probability, from one or more random accesspreambles associated with the SSB.

A wireless device may determine a first PRACH occasion from one or morePRACH occasions corresponding to a first SSB or a first CSI-RS. Forexample, the first SSB may be quasi-colocated with the first CSI-RS. Forexample, the one or more PRACH occasions may be configured by RRCmessages comprising parameters indicating an association between the oneor more PRACH occasions and the first SSB or the first CSI-RS. Forexample, the one or more random access occasions may be indicated byPDCCH. A MAC entity of the wireless device may select a PRACH occasion,for example randomly with equal probability, amongst one or moreconsecutive PRACH occasions corresponding to the first SSB or the firstCSI-RS. The MAC entity may consider a possible occurrence of measurementgaps when determining the first PRACH occasion from the one or morePRACH occasions corresponding to the first SSB or the first CSI-RS. Thewireless device may then perform a random access preamble transmissionprocedure.

A MAC entity of a wireless device may perform a random access preambletransmission procedure for each one of one or more random accesspreambles. The MAC entity may increment a preamble power ramping counter(PREAMBLE_POWER_RAMPING_COUNTER) by one. The MAC entity may select adelta preamble value (DELTA_PREAMBLE) for a power offset. The MAC entitymay set a preamble received target power(PREAMBLE_RECEIVED_TARGET_POWER) topreambleReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_POWER_RAMPING_COUNTER−1)×PREAMBLE_POWER_RAMPING_STEP,wherein the parameters of preamble transmission power are configured asdescribed above. The wireless device may determine a random access radionetwork temporary identifier (RA-RNTI) associated with a first PRACHoccasion in which the random access preamble is transmitted. The RA-RNTIassociated with the first PRACH occasion in which the random accesspreamble is transmitted is computed as:RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id, where s_id isan index of a first OFDM symbol of the first PRACH occasion (0≤s_id<14),t_id is an index of a first slot of the first PRACH occasion in a systemframe (0≤t_id<80), f_id is an index of the first PRACH occasion in thefrequency domain (0≤f_id<8), and ul_carrier_id is an UL carrier used forRandom Access Preamble transmission (0 for NUL carrier, and 1 for SULcarrier). The MAC entity may instruct the physical layer to transmit therandom access preamble via the first PRACH occasion, correspondingRA-RNTI, preamble index (PREAMBLE_INDEX), andPREAMBLE_RECEIVED_TARGET_POWER. Once a random access preamble istransmitted, a MAC entity may start a random access response window(ra-ResponseWindow) configured by RRC at a first PDCCH occasion. The MACentity may monitor the PDCCH for random access response(s) (RAR)identified by the corresponding RA-RNTI, for example, while the randomaccess response window is running. The MAC entity may receive a downlinkassignment (the RAR message) on the PDCCH for the RA-RNTI and maysuccessfully decode the received TB. The random access response (RARmessage) may comprise a MAC subPDU with a random access preambleidentifier corresponding to the preamble index (PREAMBLE_INDEX), and mayconsider the RAR reception successful. The RAR message may comprise atiming advance command. The MAC entity may process the timing advancecommand and may consider the random access procedure successfullycompleted, for example, for a contention-free random access procedure.For a contention-based random access procedure, the RAR message maycomprise an UL grant, and the MAC entity may proceed with transmissionof Msg3 for contention resolution.

A slot format may comprise downlink symbols, uplink symbols, and/orflexible symbols. For each serving cell, a wireless device may receive acommon RRC configuration message (e.g., TDD-UL-DL-ConfigCpmmon)comprising one or more parameters that indicate to the wireless deviceto set the slot format of each slot of a number of one or more slots.For example, the common RRC configuration message may comprise at leastone of: a reference subcarrier spacing (SCS) μ_(ref); and/or at leastone pattern. A first pattern of the at least one patterns may compriseat least one of: a slot configuration period of P msec; a number ofslots d_(slots) with only downlink symbols; a number of downlink symbolsd_(sym); a number of slots μ_(slots) with only uplink symbols; a numberof uplink symbols μ_(sym). The slot configuration period of P msec maycomprise s=P·2^(μ) ^(ref) slots with SCS configuration μ_(ref). From theS slots, a first d_(slots) slots may comprise one or more downlinksymbols and a last μ_(slots) slots may comprise one or more uplinksymbols. A d_(sym) symbols after the first d_(slots) may comprise one ormore downlink symbols. A μ_(sym) symbols before the last μ_(slots) slotsmay comprise one or more uplink symbols. A remaining(S−d_(slots)−μ_(slots))·N_(symb) ^(slot)−D_(sym)−˜_(sym) symbols maycomprise one or more flexible symbols. A second pattern of the at leastone patterns may be configured. The wireless device may set the slotformat of each slot of a first number of slots as indicated by the firstpattern, and may set the slot format of each slot of a second number ofslots as indicated by the second pattern.

A wireless device may receive a dedicated RRC configuration message(e.g., TDD-UL-DL-Configdedicated) comprising one or more parameters thatmay override one or more flexible symbols of each slot of a number ofslots configured by a common RRC configuration message. For example, thededicated RRC configuration message may comprise at least one of: one ormore slot configurations; and/or for each slot configuration of the oneor more slot configurations: a slot index for a slot (slotIndex); one ormore symbols of a slot (symbols) which indicates a first number of zeroor more downlink first symbols in the slot, and a second number of zeroor more uplink last symbols in the slot, and a remaining number of zeroor more flexible symbols in the slot. The wireless device may determinea slot format for each slot with a corresponding slot index of the slot(slotIndex) based on a format indicated by the one or more symbols ofthe slot (symbols).

FIG. 16A and FIG. 16B and FIG. 16C demonstrate example slot formats forone or more slots. For example, the slot format 1 in FIG. 16A comprisesof k1 symbols indicated as downlink symbols and/or uplink symbols and/orflexible symbols. For example, the slot format 2 in FIG. 16B comprisesof k2 symbols indicated as uplink symbols and/or flexible symbols. Forexample, the slot format 3 in FIG. 16C comprises of k3 symbols indicatedas downlink symbols and/or flexible symbols.

A wireless device may not expect a dedicated RRC configuration messageto indicate as uplink or as downlink a symbol that a common RRCconfiguration message indicates as a downlink or as an uplink symbol,respectively. For each slot configuration of one or more slotconfigurations indicated by the dedicated RRC configuration message, areference SCS is the reference SCS indicated by the common RRCconfiguration message. A slot configuration period and a number ofdownlink/uplink/flexible symbols in each slot of the one or more slotconfiguration period may be determined from the common/dedicated RRCconfiguration messages, and may be common to each one of one or moreconfigured BWPs.

A wireless device may receive a common RRC configuration message and/ora dedicated RRC configuration message indicating one or more symbols ina slot as downlink. The wireless device may consider the one or moresymbols to be available for reception. The wireless device may receive acommon RRC configuration message and/or a dedicated RRC configurationmessage indicating one or more symbols in a slot as uplink. The wirelessdevice may consider the one or more symbols to be available fortransmission.

One or more symbols of a slot may be indicated as flexible symbols byone or more RRC configuration messages. The wireless device may notreceive the one or more RRC configuration messages indicating a slotformat configuration. The wireless device may receive a downlink controlsignals, e.g., DCI format 1_0, DCI format 1_1, DCI format 0_1, DCIformat 0_0, and/or DCI format 2_3, scheduling downlink/uplinktransmissions. The downlink control signal (e.g., DCI format 1_0, DCIformat 1_1, and/or DCI format 0_1) or an RRC message (e.g., SIB1) mayindicate to the wireless device a reception of one or more downlinkchannels/signals (e.g., PDSCH, PDCCH, SSB, and/or CSI-RS) in the one ormore symbols of the slot. The wireless device may receive the one ormore downlink channels/signals in the one or more symbols. The downlinkcontrol signal (e.g., DCI format 1_0, DCI format 1_1, DCI format 0_0,DCI format 2_3, and/or DCI format 0_1) may indicate to the wirelessdevice a transmission of one or more uplink channels/signals (e.g.,PUSCH, PUCCH, PRACH, and/or SRS) in the one or more symbols of the slot.The wireless device may transmit the one or more uplink channels/signalsin the one or more symbols.

A wireless device may be configured by higher layers to receive a PDCCH,PDSCH, and/or CSI-RS in one or more symbols of a slot. The wirelessdevice may receive the PDCCH, PDSCH, and/or CSI-RS, for example, if thewireless device does not detect a DCI (e.g., DCI format 0_0, DCI format0_1, DCI format 1_0, DCI format 1_1, and/or DCI format 2_3) indicatingto the wireless device to transmit a PUSCH, a PUCCH, a PRACH, and/or aSRS in at least one symbol of the one or more symbols of the slot. Thewireless device may not receive the PDCCH, PDSCH, and/or CSI-RS, forexample, if the wireless device detects the DCI (e.g., DCI format 0_0,DCI format 0_1, DCI format 1_0, DCI format 1_1, and/or DCI format 2_3)indicating to the wireless device to transmit a PUSCH, a PUCCH, a PRACH,and/or a SRS in the at least one symbol of the one or more symbols ofthe slot.

A wireless device may be configured by higher layers to transmit SRS,PUCCH, PUSCH, and/or PRACH in one or more symbols of a slot. Thewireless device may detect a DCI format 1_0, DCI format 1_1, or DCIformat 0_1 indicating to the wireless device to receive CSI-RS and/orPDSCH in at least one symbol of the one or more symbols of the slot. Thewireless device may not expect to cancel the transmission in the atleast one symbol of the one or more symbols that occur, relative to alast symbol of a CORESET where the wireless device detects the DCIformat 1_0 or the DCI format 1_1 or the DCI format 0_1, after a numberof symbols that is smaller than the PUSCH preparation time, for thecorresponding wireless device processing capability. The wireless devicemay cancel the SRS, PUCCH, PUSCH, and/or PRACH transmission in remainingsymbols from the one or more symbols.

For one or more symbols of a slot that are indicated to a wirelessdevice as uplink by one or more RRC configuration messages (commonand/or dedicated), the wireless device may not receive PDCCH, PDSCH, orCSI-RS in the one or more symbols of the slot. For the one or moresymbols of the slot that are indicated to the wireless device asdownlink by the one or more RRC configuration messages (common and/ordedicated), the wireless device may not transmit PUSCH, PUCCH, PRACH,and/or SRS in the one or more symbols of the slot.

For one or more symbols of a slot that are indicated to a wirelessdevice by one or more RRC parameters for reception of SS/PBCH blocks,the wireless device may not transmit PUSCH, PUCCH, and/or PRACH in theslot if a transmission overlap with at least one symbol from the one ormore symbols and the wireless device may not transmit SRS in the one ormore symbols of the slot. The wireless device may not expect the one ormore symbols of the slot to be indicated as uplink by RRC configurationmessages (common/dedicated) when provided to the wireless device.

For one or more symbols of a slot corresponding to a valid PRACHoccasion and symbols before the valid PRACH occasion, the wirelessdevice may not receive PDCCH for Type1-PDCCH CSS set, PDSCH, or CSI-RSin the slot if a reception overlaps with at least one symbol from theone or more symbols. The wireless device may not expect the one or moresymbols of the slot to be indicated as downlink by RRC configurationmessages (common/dedicated).

If a wireless device is scheduled by a DCI format 1_1 to receive PDSCHover a plurality of slots, and if RRC configuration messages indicatethat, for a slot in the plurality of slots, at least one symbol from oneor more symbols where the wireless device is scheduled PDSCH receptionin the slot is an uplink symbol, the wireless device may not receive thePDSCH in the slot.

If a wireless device is scheduled by a DCI format 0_1 to transmit PUSCHover plurality of slots, and if RRC configuration messages indicatesthat, for a slot from the plurality of slots, at least one symbol fromone or more symbols where the wireless device is scheduled PUSCHtransmission in the slot is a downlink symbol, the wireless device maynot transmit the PUSCH in the slot.

A wireless device may be configured by higher layers with a parameterindicating one or more slot formats (SlotFormatIndicator). In anexample, a DCI format (e.g., DCI format 2_0) may be used for notifyingthe one or more slot formats. The DCI format may comprise CRC bitsscrambled by a first radio network temporary identifier (e.g.,SFI-RNTI). The first radio network temporary identifier may beconfigured by higher layers, or may be predefined, or a fixed value. Asize of the DCI format may be configured by higher layers, e.g., up to128 bits. The DCI format may comprise at least one information of one ormore slot format indicators (SFIs). The wireless device may beconfigured to monitor a group-common-PDCCH for the one or more slotformat indicators for each one of one or more serving cells configuredby the parameters indicating the one or more slot formats. For eachserving cell, the wireless device may be provided at least one of: anidentity of the serving cell; a location of an SFI-index field in theDCI format; and/or a set of slot format combinations comprising one ormore slot format combinations (slotFormatCombinations), where each ofthe one or more slot format combinations may comprise: one or more slotformats (slotFormats) for the slot format combination; a mapping for theslot format to a corresponding SFI-index field value in the DCI format(slotFormatCombinationId); and/or at least one reference SCSconfiguration.

A slot format may be identified by a corresponding format index as shownin the table in FIG. 17. FIG. 17 shows an example of slot formats of aslot, wherein each symbol in the slot may be a downlink (D) symboland/or an uplink (U) symbol and/or a flexible (F) symbol. For example,slot format 0 comprises of all downlink (D) symbols. For example, slotformat 1 comprises of all uplink (U) symbols. For example, slot format55 comprises of two downlink (D) symbols, followed by three flexible (F)symbols, followed by three uplink (U) symbols, followed by six downlink(D) symbols.

FIG. 18A illustrates a slot format combination. In an example, the slotformat combination may comprise k slots. In an example, each slot of theslot format combination may have a slot format (for example, slot0 mayhave slot format SF0, slot1 may have slot format SF1, slot2 may haveslot format SF2, slot3 may have slot format SF3, slot4 may have slotformat SF4, slot5 may have slot format SF5 and slot k may have slotformat SFk). In an example, two or more of SF0, SF1, SF2, SF3, SF4, SF5and SFk may correspond to different slot formats. In an example, two ormore of SF0, SF1, SF2, SF3, SF4, SF5 and SFk may correspond to the sameslot format. In an example, two or more slot formats of SF0, SF1, SF2,SF3, SF4, SF5 and SFk may be same. As shown in FIG. 18B, a plurality ofslot format combinations of a cell (e.g. slot format combination 0, slotformat combination 1, slot format combination 2, slot format combination3, . . . , and slot format combination m) may be configured to awireless device via RRC messages. In an example, the plurality of slotformat combinations may be slot format combinations of NR system. In anexample, the plurality of slot format combinations may be slot formatcombinations designed based on an interference condition of NR-U system.In an example, the plurality of slot format combinations may be slotformat combinations designed based on a channel condition of NR-Usystem. In an example, a slot format combination may be indicated to awireless device via downlink control channel. In an example, the slotformat combination may be indicated to the wireless device via a PDCCH.In an example, the slot format combination may be indicated to thewireless device via a GC-PDCCH.

In an example, and as shown in FIG. 18B, the plurality of the slotformat combinations may be parted into a plurality of slot formatcombination sets (for example, slot format combination0, slot formatcombination set1, slot format combination set 2, . . . , and slot formatcombination set n). In an example, the plurality of slot formatcombination sets may be configured to a wireless device via RRCmessages. In an example, the number of slot format combinations in eachof the slot format combination sets may be different. In an example, thenumber of slot format combinations in each of the slot formatcombination sets may be same. In an example, a time length of a slotformat combination in each of the slot format combination sets may beequal to a time length of a channel occupancy time (COT). In an example,the time length of the slot format combination in each of the slotformat combination sets may be larger than the time length of the COT.

A SFI-index field value in a DCI format may indicate to a wirelessdevice a slot format for each of one or more slots in a number of slotsfor each DL BWP and/or each UL BWP starting from a slot where thewireless device detects the DCI format.

For one or more symbols of a slot, a wireless device may not expect todetect a DCI format (e.g., DCI format 2_0) with an SFI-index field valueindicating the one or more symbols of the slot as uplink and to detect aDCI format 1_0, a DCI format 1_1, or DCI format 0_1 indicating to thewireless device to receive PDSCH or CSI-RS in the one or more symbols ofthe slot.

For one or more symbols of a slot, a wireless device may not expect todetect a DCI format (e.g., DCI format 2_0) with an SFI-index field valueindicating the one or more symbols in the slot as downlink and to detecta DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, DCIformat 2_3, or a RAR UL grant indicating to the wireless device totransmit PUSCH, PUCCH, PRACH, or SRS in the one or more symbols of theslot.

For one or more symbols of a slot that are indicated as downlink/uplinkby RRC configuration messages (e.g., TDD-UL-DL-ConfigurationCommon, orTDD-UL-DL-ConfigDedicated), the wireless device may not expect to detecta DCI format (e.g., DCI format 2_0) with an SFI-index field valueindicating the one or more symbols of the slot as uplink/downlink,respectively, or as flexible.

For one or more symbols of a slot indicated to a wireless device by RRCmessages (e.g., ssb-PositionsInBurst in SystemInformationBlockType1 orssb-PositionsInBurst in ServingCellConfigCommon) for reception ofSS/PBCH blocks, the wireless device may not expect to detect a DCIformat (e.g., DCI format 2_0) with an SFI-index field value indicatingthe one or more symbols of the slot as uplink.

For one or more symbols of a slot indicated to a wireless device by RRCmessages (e.g., prach-ConfigurationIndex in RACH-ConfigCommon) for PRACHtransmissions, the wireless device may not expect to detect a DCI format(e.g., DCI format 2_0) with an SFI-index field value indicating the oneor more symbols of the slot as downlink.

For one or more symbols of a slot indicated to a wireless device by RRCmessages (e.g., pdcch-ConfigSIB1 in MIB) for a CORESET for Type0-PDCCHCSS set, the wireless device may not expect to detect a DCI format(e.g., DCI format 2_0) with an SFI-index field value indicating the oneor more symbols of the slot as uplink.

For one or more symbols of a slot indicated to a wireless device asflexible by RRC configuration messages (e.g.,TDD-UL-DL-ConfigurationCommon and TDD-UL-DL-ConfigDedicated), or whenRRC configuration messages are not provided to the wireless device, thewireless device may detect a DCI format (e.g. DCI format 2_0) providinga format for the slot. If at least one symbol of the one or more symbolsis a symbol in a CORESET configured to the wireless device for PDCCHmonitoring, the wireless device may receive PDCCH in the CORESET only ifan SFI-index field value in the DCI format indicates that the at leastone symbol is a downlink symbol. If the SFI-index field value in the DCIformat indicates the one or more symbols of the slot as flexible and thewireless device detects a DCI format 1_0, DCI format 1_1, or DCI format0_1 indicating to the wireless device to receive PDSCH or CSI-RS in theone or more symbols of the slot, the wireless device may receive PDSCHor CSI-RS in the one or more symbols of the slot. If the SFI-index fieldvalue in the DCI format indicates the one or more symbols of the slot asflexible and the wireless device detects a DCI format 0_0, DCI format0_1, DCI format 1_0, DCI format 1_1, DCI format 2_3, or a RAR UL grantindicating to the wireless device to transmit PUSCH, PUCCH, PRACH, orSRS in the one or more symbols of the slot, the wireless device maytransmit the PUSCH, PUCCH, PRACH, or SRS in the one or more symbols ofthe slot. If the SFI-index field value in the DCI format indicates theone or more symbols of the slot as flexible, and the wireless devicedoes not detect a DCI format 1_0, DCI format 1_1, or DCI format 0_1indicating to the wireless device to receive PDSCH or CSI-RS, or thewireless device does not detect a DCI format 0_0, DCI format 0_1, DCIformat 1_0, DCI format 1_1, DCI format 2_3, or a RAR UL grant indicatingto the wireless device to transmit PUSCH, PUCCH, PRACH, or SRS in theone or more symbols of the slot, the wireless device may not transmit orreceive in the one or more symbols of the slot. If the wireless deviceis configured by higher layers to receive PDSCH or CSI-RS in the one ormore symbols of the slot, the wireless device may receive the PDSCH orthe CSI-RS in the one or more symbols of the slot only if an SFI-indexfield value in the DCI format indicates the one or more symbols of theslot as downlink. If the wireless device is configured by higher layersto transmit PUCCH, or PUSCH, or PRACH in the one or more symbols of theslot, the wireless device transmits the PUCCH, or the PUSCH, or thePRACH in the slot only if an SFI-index field value in the DCI formatindicates the one or more symbols of the slot as uplink. If the wirelessdevice is configured by higher layers to transmit SRS in the one or moresymbols of the slot, the wireless device transmits the SRS only in asubset of symbols from the one or more symbols of the slot indicated asuplink symbols by an SFI-index field value in the DCI format. A wirelessdevice may not expect to detect an SFI-index field value in the DCIformat indicating the one or more symbols of the slot as downlink andalso detect a DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format1_1, DCI format 2_3, or a RAR UL grant indicating to the wireless deviceto transmit SRS, PUSCH, PUCCH, or PRACH, in at least one symbol of theone or more symbols of the slot. A wireless device may not expect todetect an SFI-index field value in the DCI format indicating the one ormore symbols of the slot as downlink or flexible if the one or moresymbols of the slot comprises at least one symbol corresponding to anyrepetition of a PUSCH transmission activated by an UL Type 2 grantPDCCH. A wireless device may not expect to detect an SFI-index fieldvalue in the DCI format indicating the one or more symbols of the slotas uplink and also detect a DCI format 1_0 or DCI format 1_1 or DCIformat 0_1 indicating to the wireless device to receive PDSCH or CSI-RSin at least one symbol of the one or more symbols of the slot.

If a wireless device is configured by higher layers to receive a CSI-RSor a PDSCH in one or more symbols of a slot and the wireless devicedetects a DCI format (e.g., DCI format 2_0) with a slot format valuethat indicates a slot format with a subset of symbols from the one ormore symbols as uplink or flexible, or the wireless device detects a DCIformat 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, or DCIformat 2_3 indicating to the wireless device to transmit PUSCH, PUCCH,SRS, or PRACH in at least one symbol in the one or more symbols, thewireless device cancels the CSI-RS reception in the one or more symbolsof the slot or cancels the PDSCH reception in the slot.

A wireless device may be configured by higher layers to transmit SRS, orPUCCH, or PUSCH, or PRACH in one or more symbols of a slot and thewireless device may detect a DCI format (e.g., DCI format 2_0) with aslot format value that indicates a slot format with a subset of symbolsfrom the one or more symbols as downlink or flexible, or the wirelessdevice may detect a DCI format 1_0, DCI format 1_1, or DCI format 0_1indicating to the wireless device to receive CSI-RS or PDSCH in a subsetof symbols from the one or more symbols. The wireless device may notexpect to cancel the transmission in symbols from the subset of symbolsthat occur, relative to a last symbol of a CORESET where the wirelessdevice detects the DCI format 2_0 or the DCI format 1_0 or the DCIformat 1_1 or the DCI format 0_1, after a number of symbols that issmaller than the PUSCH preparation time for the corresponding PUSCHprocessing capability. The wireless device may cancel the PUCCH, orPUSCH, or PRACH transmission in remaining symbols from the one or moresymbols and may cancel the SRS transmission in remaining symbols fromthe subset of symbols.

A wireless device may assume that flexible symbols in a CORESETconfigured to the wireless device for PDCCH monitoring are downlinksymbols if the wireless device does not detect an SFI-index field valuein a DCI format (e.g., DCI format 2_0) indicating one or more symbols ofa slot as flexible or uplink and the wireless device does not detect aDCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, or DCIformat 2_3 indicating to the wireless device to transmit SRS, PUSCH,PUCCH, or PRACH in the one or more symbols.

For one or more symbols of a slot that are indicated as flexible by RRCconfiguration messages (e.g. TDD-UL-DL-ConfigurationCommon, andTDD-UL-DL-ConfigDedicated), or when RRC configuration messages are notprovided to a wireless device, the wireless device may not detect a DCIformat (e.g., DCI format 2_0) providing a slot format for the slot. Thewireless device may receive PDSCH or CSI-RS in the one or more symbolsof the slot if the wireless device receives a corresponding indicationby a DCI format 1_0, DCI format 1_1, or DCI format 0_1. The wirelessdevice may transmit PUSCH, PUCCH, PRACH, or SRS in the one or moresymbols of the slot if the wireless device receives a correspondingindication by a DCI format 0_0, DCI format 0_1, DCI format 1_0, DCIformat 1_1, or DCI format 2_3. The wireless device may receive PDCCH. Ifthe wireless device is configured by higher layers to receive PDSCH orCSI-RS in the one or more symbols of the slot, the wireless device maynot receive the PDSCH or the CSI-RS in the one or more symbols of theslot. If the wireless device is configured by higher layers to transmitSRS, or PUCCH, or PUSCH, or PRACH in the one or more symbols of theslot, the wireless device may not transmit the PUCCH, or the PUSCH, orthe PRACH in the slot and may not transmit the SRS in symbols from theone or more symbols in the slot, if any, starting from a symbol that isa number of symbols equal to the PUSCH preparation time for thecorresponding PUSCH timing capability after a last symbol of a CORESETwhere the wireless device is configured to monitor PDCCH for DCI format2_0. The wireless device may not expect to cancel the transmission ofthe SRS, or the PUCCH, or the PUSCH, or the PRACH in symbols from theone or more symbols in the slot, if any, starting before a symbol thatis a number of symbols equal to the PUSCH preparation time for thecorresponding PUSCH timing capability after a last symbol of a CORESETwhere the wireless device is configured to monitor PDCCH for DCI format2_0.

For unpaired spectrum operation for a wireless device on a cell in afrequency band of FR1, and when the scheduling restrictions due to RRMmeasurements are not applicable, if the wireless device detects a DCIformat 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, or DCIformat 2_3 indicating to the wireless device to transmit in one or moresymbols, the wireless device may not be required to perform RRMmeasurements based on a SS/PBCH block or CSI-RS reception on a differentcell in the frequency band if the SS/PBCH block or CSI-RS receptioncomprises at least one symbol from the set of symbols.

The amount of data traffic carried over cellular networks is expected toincrease for many years to come. The number of users/devices isincreasing, and each user/device accesses an increasing number andvariety of services, e.g. video delivery, large files, images. Thisrequires not only high capacity in the network, but also provisioning ofvery high data rates to meet customer expectations on interactivity andresponsiveness. More spectrum is therefore needed for cellular operatorsto meet the increasing demand Considering user expectations of high datarates along with seamless mobility, it is beneficial that more spectrumbe made available for deploying macro cells as well as small cells forcellular systems.

Striving to meet the market demands, there has been increasing interestfrom operators in deploying some complementary access utilizingunlicensed spectrum to meet the traffic growth. This is exemplified bythe large number of operator-deployed Wi-Fi networks and the 3GPPstandardization of interworking solutions with Wi-Fi, e.g., LTE/WLANinterworking. This interest indicates that unlicensed spectrum, whenpresent, may be an effective complement to licensed spectrum forcellular operators to address the traffic explosion in some scenarios,such as hotspot areas. For example, licensed assisted access (LAA)and/or new radio on unlicensed band(s) (NR-U) may offer an alternativefor operators to make use of unlicensed spectrum while managing oneradio network, thus offering new possibilities for optimizing thenetwork's efficiency.

In an example embodiment, Listen-before-talk (LBT) may be implementedfor transmission in an unlicensed cell. The unlicensed cell may bereferred to as a LAA cell and/or a NR-U cell. The unlicensed cell may beoperated as non-standalone with an anchor cell in a licensed band orstandalone without an anchor cell in a licensed band. LBT may comprise aclear channel assessment (CCA). For example, in an LBT procedure,equipment may apply a CCA before using the unlicensed cell or channel.The CCA may comprise an energy detection that determines the presence ofother signals on a channel (e.g., channel is occupied) or absence ofother signals on a channel (e.g., channel is clear). A regulation of acountry may impact the LBT procedure. For example, European and Japaneseregulations mandate the usage of LBT in the unlicensed bands, such asthe 5 GHz unlicensed band. Apart from regulatory requirements, carriersensing via LBT may be one way for fairly sharing the unlicensedspectrum among different devices and/or networks attempting to utilizethe unlicensed spectrum.

In an example embodiment, discontinuous transmission on an unlicensedband with limited maximum transmission duration may be enabled. Some ofthese functions may be supported by one or more signals to betransmitted from the beginning of a discontinuous downlink transmissionin the unlicensed band. Channel reservation may be enabled by thetransmission of signals, by an NR-U node, after or in response togaining channel access based on a successful LBT operation. Other nodesmay receive the signals (e.g., transmitted for the channel reservation)with an energy level above a certain threshold that may sense thechannel to be occupied. Functions that may need to be supported by oneor more signals for operation in unlicensed band with discontinuousdownlink transmission may comprise one or more of the following:detection of the downlink transmission in unlicensed band (comprisingcell identification) by wireless devices; time & frequencysynchronization of wireless devices.

In an example embodiment, downlink transmission and frame structuredesign for operation in an unlicensed band may employ subframe,(mini-)slot, and/or symbol boundary alignment according to timingrelationships across serving cells aggregated by carrier aggregation.This may not imply that base station transmissions start at thesubframe, (mini-)slot, and/or symbol boundary. Unlicensed cell operation(e.g., LAA and/or NR-U) may support transmitting PDSCH, for example,when not all OFDM symbols are available for transmission in a subframeaccording to LBT. Delivery of necessary control information for thePDSCH may also be supported.

An LBT procedure may be employed for fair and friendly coexistence of a3GPP system (e.g., LTE and/or NR) with other operators and technologiesoperating in unlicensed spectrum. For example, a node attempting totransmit on a carrier in unlicensed spectrum may perform a CCA as a partof an LBT procedure to determine if the channel is free for use. The LBTprocedure may involve energy detection to determine if the channel isbeing used. For example, regulatory requirements in some regions, e.g.,in Europe, specify an energy detection threshold such that if a nodereceives energy greater than the threshold, the node assumes that thechannel is being used and not free. While nodes may follow suchregulatory requirements, a node may optionally use a lower threshold forenergy detection than that specified by regulatory requirements. A radioaccess technology (e.g., LTE and/or NR) may employ a mechanism toadaptively change the energy detection threshold. For example, NR-U mayemploy a mechanism to adaptively lower the energy detection thresholdfrom an upper bound. An adaptation mechanism may not preclude static orsemi-static setting of the threshold. In an example Category 4 LBT (CAT4LBT) mechanism or other type of LBT mechanisms may be implemented.

Various example LBT mechanisms may be implemented. In an example, forsome signals, in some implementation scenarios, in some situations,and/or in some frequencies no LBT procedure may be performed by thetransmitting entity. In an example, Category 1 (CAT1, e.g., no LBT) maybe implemented in one or more cases. For example, a channel inunlicensed band may be hold by a first device (e.g., a base station forDL transmission), and a second device (e.g., a wireless device) takesover the for a transmission without performing the CAT1 LBT. In anexample, Category 2 (CAT2, e.g. LBT without random back-off and/orone-shot LBT) may be implemented. The duration of time determining thatthe channel is idle may be deterministic (e.g., by a regulation). A basestation may transmit an uplink grant indicating a type of LBT (e.g.,CAT2 LBT) to a wireless device. CAT1 LBT and CAT2 LBT may be employedfor Channel occupancy time (COT) sharing. For example, a base station (awireless device) may transmit an uplink grant (resp. uplink controlinformation) comprising a type of LBT. For example, CAT1 LBT and/or CAT2LBT in the uplink grant (or uplink control information) may indicate, toa receiving device (e.g., a base station, and/or a wireless device) totrigger COT sharing. In an example, Category 3 (CAT3, e.g. LBT withrandom back-off with a contention window of fixed size) may beimplemented. The LBT procedure may have the following procedure as oneof its components. The transmitting entity may draw a random number Nwithin a contention window. The size of the contention window may bespecified by the minimum and maximum value of N. The size of thecontention window may be fixed. The random number N may be employed inthe LBT procedure to determine the duration of time that the channel issensed to be idle before the transmitting entity transmits on thechannel. In an example, Category 4 (CAT4, e.g. LBT with random back-offwith a contention window of variable size) may be implemented. Thetransmitting entity may draw a random number N within a contentionwindow. The size of contention window may be specified by the minimumand maximum value of N. The transmitting entity may vary the size of thecontention window when drawing the random number N. The random number Nmay be used in the LBT procedure to determine the duration of time thatthe channel is sensed to be idle before the transmitting entitytransmits on the channel.

In an example, a wireless device may employ uplink (UL) LBT. The UL LBTmay be different from a downlink (DL) LBT (e.g. by using different LBTmechanisms or parameters) for example, since the NR-U UL may be based onscheduled access which affects a wireless device's channel contentionopportunities. Other considerations motivating a different UL LBTcomprise, but are not limited to, multiplexing of multiple wirelessdevices in a subframe (slot, and/or mini-slot).

In an example, DL transmission burst(s) may be a continuous (unicast,multicast, broadcast, and/or combination thereof) transmission by a basestation (e.g., to one or more wireless devices) on a carrier component(CC). UL transmission burst(s) may be a continuous transmission from oneor more wireless devices to a base station on a CC. In an example, DLtransmission burst(s) and UL transmission burst(s) on a CC in anunlicensed spectrum may be scheduled in a TDM manner over the sameunlicensed carrier. Switching between DL transmission burst(s) and ULtransmission burst(s) may require an LBT (e.g., CAT1 LBT, CAT2 LBT, CAT3LBT, and/or CAT4 LBT). For example, an instant in time may be part of aDL transmission burst or an UL transmission burst.

Channel occupancy time (COT) sharing may be employed in NR-U. COTsharing may be a mechanism by which one or more wireless devices share achannel that is sensed as idle by at least one of the one or morewireless devices. For example, one or more first devices may occupy achannel via an LBT (e.g., the channel is sensed as idle based on CAT4LBT) and one or more second devices may share the channel using an LBT(e.g., 25 us LBT) within a maximum COT (MCOT) limit. For example, theMCOT limit may be given per priority class, logical channel priority,and/or wireless device specific. COT sharing may allow a concession forUL in unlicensed band. For example, a base station may transmit anuplink grant to a wireless device for a UL transmission. For example, abase station may occupy a channel and transmit, to one or more wirelessdevices a control signal indicating that the one or more wirelessdevices may use the channel. For example, the control signal maycomprise an uplink grant and/or a particular LBT type (e.g., CAT1 LBTand/or CAT2 LBT). The one or more wireless device may determine COTsharing based at least on the uplink grant and/or the particular LBTtype. The wireless device may perform UL transmission(s) with dynamicgrant and/or configured grant (e.g., Type 1, Type2, autonomous UL) witha particular LBT (e.g., CAT2 LBT such as 25 us LBT) in the configuredperiod, for example, if a COT sharing is triggered. A COT sharing may betriggered by a wireless device. For example, a wireless deviceperforming UL transmission(s) based on a configured grant (e.g., Type 1,Type2, autonomous UL) may transmit an uplink control informationindicating the COT sharing (UL-DL switching within a (M)COT). A startingtime of DL transmission(s) in the COT sharing triggered by a wirelessdevice may be indicated in one or more ways. For example, one or moreparameters in the uplink control information indicate the starting time.For example, resource configuration(s) of configured grant(s)configured/activated by a base station may indicate the starting time.For example, a base station may be allowed to perform DL transmission(s)after or in response to UL transmission(s) on the configured grant(e.g., Type 1, Type 2, and/or autonomous UL). There may be a delay(e.g., at least 4 ms) between the uplink grant and the UL transmission.The delay may be predefined, semi-statically configured (via an RRCmessage) by a base station, and/or dynamically indicated (e.g., via anuplink grant) by a base station. The delay may not be accounted in theCOT duration.

In an example, single and multiple DL to UL and UL to DL switchingwithin a shared COT may be supported. Example LBT requirements tosupport single or multiple switching points, may comprise: for a gap ofless than 16 us: no-LBT may be used; for a gap of above 16 us but doesnot exceed 25 us: one-shot LBT may be used; for single switching point,for a gap from DL transmission to UL transmission exceeds 25 us:one-shot LBT may be used; for multiple switching points, for a gap fromDL transmission to UL transmission exceeds 25 us, one-shot LBT may beused.

In an example, a signal that facilitates its detection with lowcomplexity may be useful for wireless device power saving, improvedcoexistence, spatial reuse at least within the same operator network,serving cell transmission burst acquisition, etc. In an example, a radioaccess technology (e.g., LTE and/or NR) may employ a signal comprisingat least SS/PBCH block burst set transmission. Other channels andsignals may be transmitted together as part of the signal. In anexample, the signal may be a discovery reference signal (DRS). There maybe no gap within a time span that the signal is transmitted at leastwithin a beam. In an example, a gap may be defined for beam switching.In an example, a block-interlaced based PUSCH may be employed. In anexample, the same interlace structure for PUCCH and PUSCH may be used.In an example, interlaced based PRACH may be used.

In an example, initial active DL/UL BWP may be approximately 20 MHz fora first unlicensed band, e.g., in a 5 GHz unlicensed band. An initialactive DL/UL BWP in one or more unlicensed bands may be similar (e.g.,approximately 20 MHz in a 5 GHz and/or 6 GHz unlicensed spectrum), forexample, if similar channelization is used in the one or more unlicensedbands (e.g., by a regulation).

In an example, HARQ acknowledge and negative acknowledge (A/N) for thecorresponding data may be transmitted in a shared COT (e.g., with a CAT2LBT). In some examples, the HARQ A/N may be transmitted in a separateCOT (e.g., the separate COT may require a CAT4 LBT). In an example, whenUL HARQ feedback is transmitted on unlicensed band, a radio accesstechnology (e.g., LTE and/or NR) may support flexible triggering andmultiplexing of HARQ feedback for one or more DL HARQ processes. HARQprocess information may be defined independent of timing (e.g., timeand/or frequency resource) of transmission. In an example, UCI on PUSCHmay carry HARQ process ID, NDI, RVID. In an example, Downlink FeedbackInformation (DFI) may be used for transmission of HARQ feedback forconfigured grant.

In an example, CBRA and CFRA may be supported on SpCell. CFRA may besupported on SCells. In an example, an RAR may be transmitted viaSpCell, e.g., non-standalone scenario. In an example, an RAR may betransmitted via SpCell and/or SCell, e.g., standalone scenario. In anexample, a predefined HARQ process ID for an RAR.

In an example, carrier aggregation between licensed band NR (PCell) andNR-U (SCell) may be supported. In an example, NR-U SCell may have bothDL and UL, or DL-only. In an example, dual connectivity between licensedband LTE (PCell) and NR-U (PSCell) may be supported. In an example,Stand-alone NR-U where all carriers are in one or more unlicensed bandsmay be supported. In an example, an NR cell with DL in unlicensed bandand UL in licensed band or vice versa may be supported. In an example,dual connectivity between licensed band NR (PCell) and NR-U (PSCell) maybe supported.

In an example, a radio access technology (e.g., LTE and/or NR) operatingbandwidth may be an integer multiple of 20 MHz, for example, if absenceof Wi-Fi cannot be guaranteed (e.g. by regulation) in an unlicensed band(e.g., 5 GHz, 6 GHZ, and/or sub-7 GHz) where the radio access technology(e.g., LTE and/or NR) is operating. In an example, a wireless device mayperformance or more LBTs in units of 20 MHz. In an example, receiverassisted LBT (e.g., RTS/CTS type mechanism) and/or on-demand receiverassisted LBT (e.g., for example receiver assisted LBT enabled only whenneeded) may be employed. In an example, techniques to enhance spatialreuse may be used.

In an operation in an unlicensed band (e.g., LTE eLAA/feLAA and/orNR-U), a wireless device may measure (averaged) received signal strengthindicator (RSSI) and/or may determine a channel occupancy (CO) of one ormore channels. For example, the wireless device may report channeloccupancy and/or RSSI measurements to the base station. It may bebeneficial to report a metric to represent channel occupancy and/ormedium contention. The channel occupancy may be defined as a portion(e.g., percentage) of time that RSSI was measured above a configuredthreshold. The RSSI and the CO measurement reports may assist the basestation to detect the hidden node and/or to achieve a load balancedchannel access to reduce the channel access collisions.

Channel congestion may cause an LBT failure. The probability ofsuccessful LBT may be increased for random access and/or for datatransmission if, for example, the wireless device selects thecell/BWP/channel with the lowest channel congestion or load. Forexample, channel occupancy aware RACH procedure may be considered toreduce LBT failure. For example, the random access backoff time for thewireless device may be adjusted based on channel conditions (e.g., basedon channel occupancy and/or RSSI measurements). For example, a basestation may (semi-statically and/or dynamically) transmit a randomaccess backoff. For example, the random access backoff may bepredefined. For example, the random access backoff may be incrementedafter or in response to one or more random access response receptionfailures corresponding to one or more random access preamble attempts.

The frame structure of NR in unlicensed spectrum (NR-U) may be animportant feature for fair coexistence with other radio accesstechnologies (RATs) (e.g., LTE and WLAN) and for performance of NR-U interms of, for example, spectrum efficiency, reliability, and latency. Tohave a simplified and unified system, the frame structure of NR-U mayinherit features of NR in licensed spectrum.

In an example, channel occupancy time (COT) is defined in ETSI BRANregulation as a total time that a wireless device may make use of anoperating channel in an unlicensed band, after which the wireless devicemay perform a new extended clear channel assessment (CCA) (for example,LBT CAT4) to continue using the operating channel. The concept of COT(also known as transmission opportunity period (TXOP) in IEEE) isfurther extended in 3GPP eLAA and IEEE 802.11 HCCA to enablebi-directional transmission between an eNB (AP) and a wireless device(STA) without performing an LBT CAT4 in COT. In an example, as COT maystart at any time with variable duration, the frame structure design forNR-U may be flexible and efficient enough to make use of COT.

In NR licensed spectrum, a self-contained slot with a bi-directionalstructure (e.g., a structure with one or more downlink resources and oneor more uplink resources as shown in FIG. 19) is supported. Therefore, abi-directional slot transmission may also be supported in NR-U.Different slot configurations may be configured for different scenarios.It may provide more flexibility to construct a bi-directional COTstructure, which may comprise bi-directional transmission for one ormore slots in the COT structure. In an example, and as shown in FIG. 18,a COT may comprise a plurality of bi-directional slots (e.g. the COT maycomprise k bi-directional slots). A bi-directional slot may comprisedownlink symbols/resources, uplink symbols/resources, and a gapduration. In an example, the gap duration may comprise a guard periodfrom downlink receiving to uplink transmitting. The bi-directional slotsmay allow for multiple DL/UL switching points within the COT of NR-U,which may allow for fast and simplified procedures of scheduling andfeedback in unlicensed spectrum, including fast link adaptation andreduced number of HARQ processes. The multiple DL/UL switching pointswithin the COT of NR-U may allow for more efficient resource utilizationin unlicensed spectrum.

In an example, a wireless device may benefit from an indication of theDL/UL configuration of a bi-directional COT. For example, by identifyingthe DL portion(s) of a COT, a wireless device may only monitor the DLportion(s) of the COT for DL control information instead of monitoringevery slot in the COT to reduce power consumption. It may also benefitfor the wireless device to average CSI measurements when the wirelessdevice obtains an accurate position of downlink resource. In anotherexample, by identifying UL portion(s) of the COT, the wireless devicemay be able to prepare UL data at an earlier time point and use aone-shot LBT for UL transmission within the COT, without needing tosignal LBT type. This may reduce signaling overhead.

Semi static DL/UL configuration by RRC signaling may be supported inboth LTE and NR licensed spectrum. In unlicensed spectrum, it may bedesirable to vary a COT structure frequently due to, for example,uncertainty of an LBT result and the interference environment in theunlicensed spectrum. Therefore, semi static DL/UL configuration may notbe suitable for NR-U. Instead, a dynamic DL/UL configuration may bepreferred. In an example, a COT structure indication may be carried in acommon control channel, for example, a GC-PDCCH or enhanced GC-PDCCH. Inan example, a PDCCH designed for NR-U may be used to carry the COTstructure indication.

A wireless device may assume a presence of a signal, e.g., a DMRS in any[PDCCH or GC-PDCCH] transmission. The wireless device may detecttransmission bursts by the serving base station based on the presence ofthe signal. The signal may enable power saving by not performing blinddecodes to detect the transmission bursts. The payload of a PDCCH and/orGC-PDCCH transmission may comprise information regarding COT structure.For example, the wireless device may use the COT structure informationfor power saving. For example, the wireless device may indicate the COTsharing information in an uplink control information (UCI) wheninitiating a COT. The COT structure information in the downlink maycomprise at least one of: DL/UL/Flexible symbols and switching points(like SFI); PDCCH monitoring indicator; SFI information(start/end/next); occupied bandwidth; COT duration, end of COT;additional SFI entries for partial slots; SFI for outside COT; and/orCOT sharing (e.g., for configured grant sharing).

In an example, a DCI format (e.g., DCI format 2_0) may provide COTstructure indication. It may be beneficial for the DCI format toindicate the COT structure in the time domain. For example, a DMRS ofGC-PDCCH may be used for COT structure indication. For example,end-of-COT and/or COT duration may be indicated as an extension of SFIsignaling in the DCI format. For example, a signal may be transmittedprior to a DL transmission burst and GC-PDCCH indicating the COTstructure. For example, the signal may indicate that the channel may beoccupied as DL during a duration from the detection point of the signalto at least the next occasion for GC-PDCCH. The GC-PDCCH may indicate adirection (DL, UL, or flexible), COT length, and/or information relatedto occupied bandwidth. For example, Additional formats of SFI in the DCIformat may be used for COT structure indication. For example, the COTformat may comprise further COT related information, e.g., COT structurein frequency domain, and/or PDCCH monitoring periodicity inside the COT.For example, the COT length may be explicitly indicated in the DCIformat. For example, the COT length may be implicitly determined basedon a number of slots (e.g., full and/or partial slots) in the SFI.

A base station may configure one or more parameters comprising COTstructure. In an example, the base station may associate a set of slotformat combinations comprising a DL/UL configuration of one or moreslots with a corresponding slot format indicator (SFI)-index fieldvalue, e.g., in DCI format 2_0. A base station may configure a firstmini-slot or slot after or in response to a successful LBT to carry aCOT format indicator (CFI). The base station may configure the CFI tocomprise at least the following: an entire and/or remaining duration ofthe COT; expected DL/UL and/or UL/DL switching points; indication on LBTcategories to be performed by the wireless device after a DL/ULswitching point.

Semi-static resource allocation of PRACH may be supported as a baselinedesign for an operation of a radio access technology (e.g., LTE and/orNR) in an unlicensed band. A base station may semi-statically configurea wireless device with one or more random access resources, e.g., one ormore time resources, one or more frequency resources, and one or morepreambles. One or more PRACH periodicities may be supported, e.g., 10,20, 40, 60, and 160 ms. A wireless device may wait until the nextconfigured PRACH occasion without transmitting a random access preamble,for example, if the wireless device determines an LBT failure, which mayresult in an increased latency associated with a random access procedurefor the wireless device.

There may be one or more enhancements implemented in a radio accesstechnology (e.g., LTE and/or NR) for an operation in an unlicensed band.In an example, one or more transmission opportunities for PRACH may beconfigured in time, frequency, code, and/or any combination thereof. Forexample, a base station may configure, for contention-free and/orcontention-based RA, one or more PRACH resources across one or more LBTsub-bands/carriers for a wireless device. For example, in the timedomain, a base station may configure for a wireless device one or morePRACH resources dynamically, e.g., via DCI for connected mode wirelessdevice. For example, PRACH resources configured to a wireless device maycomprise one or more first PRACH resources dynamically configured (e.g.,via DCI) and/or one or more second PRACH resource semi-staticallyconfigured (e.g., via an RRC message). For example, a base station maydynamically configure one or more PRACH resources within a COT where thebase station transmits one or more SSBs. For example, the one or morePRACH resources may be dynamically scheduled, e.g., via paging for idlemode wireless device and/or via DCI (or any control signal) for aconnected mode wireless device. For example, the one or more PRACHresources may follow one or more SSBs (e.g., DRS transmission).

A wireless device may perform LBT for accessing a channel beforetransmitting PRACH in an unlicensed band. The wireless device maytransmit the PRACH, for example, if the channel is free. The wirelessdevice may postpone the PRACH transmission, for example, if the channelis busy. A base station may reserve a time duration for the wirelessdevice before transmitting PRACH to perform LBT, e.g., an LBT gap forRACH occasion (RO). The base station may dynamically schedule RACHoccasions via a DCI. The wireless device may transmit at least onepreamble via the RACH occasions without LBT (or with performing aparticular LBT, e.g., CAT2 LBT), for example, if the gap between DL/ULswitching point (e.g., between the last DL symbol and a selected RACHoccasion) is small (e.g., less than 16 micro seconds or between 16 and25 micro seconds).

A base station may share an acquired COT with a wireless device forrandom access procedure. The base station may allow the wireless deviceto multiplex PRACH resources in UL portion of an acquired COT. Forexample, the base station may transmit, to one or more wireless devices,an indication via a group-common PDCCH (GC-PDCCH) to schedule PRACHresources within the acquired COT, e.g., for connected, inactive, and/oridle mode wireless device(s). In an example, the base station maytransmit the PDCCH (e.g., GC-PDCCH) to schedule resources after one ormore SSBs (e.g., in an RMSI and/or in a DCI). In an example, thewireless device may perform one-shot (CAT2) LBT or no LBT for randomaccess preamble (Msg1) and Msg3 transmission in the COT acquired by thebase station, for example, the wireless device receives the indication.

A wireless device may share a COT with a base station, for example, whenthe wireless device acquires the COT based on, for example, CAT4 LBT.For example, the wireless device may acquire the COT for Msg1 and/orMsg3 transmission(s). The base station may perform one-shot (CAT2) LBTor no LBT before Msg2 and Msg4 transmission in the COT.

Dynamic PRACH resource allocation may be complementary considered inaddition to the semi-statically allocated PRACH resources. In anexample, scheduling of PRACH may be triggered by DCI, e.g., a groupcommon PDCCH. The scheduling information may comprise time and frequencyresource allocation for PRACH. In an example, to reduce signalingoverhead, only parameters subject to LBT results may be configured inDCI, e.g., starting OFDM symbol and frequency resources. For example,one or more parameters comprising PRACH periodicity, preamble format,and RO number per PRACH slot may be acquired by RMSI. The DCI triggerscheme may be used for connected mode wireless devices. The DCI triggerscheme may provide robustness against LBT failures, for example byallowing PRACH resources being multiplexed in UL portion of a shared COTacquired by the base station. A GC-PDCCH may be used to schedule PRACHresources in the COT. The DCI trigger scheme may be used for idle modewireless devices. The COT may be shared between the PRACH resourcetrigger (e.g., the DCI or the DRS) and the preamble transmission. TheCOT sharing for PRACH transmission may reduce the effect of a firstwireless device performing LBT blocking a second wireless device(inter-wireless device blocking).

PRACH resources may be located inside or outside a basestation-initiated COT. PRACH transmissions may follow a first type ofLBT mechanism (e.g., CAT-2 or CAT-4 LBT) accordingly. The base stationmay indicate whether RACH occasion is located inside or outside the COTto the base station. For example, COT length indication may be signaledin a DCI that precedes the RACH occasion. For example, the DCI may beused to indicate COT reservation to cover the RACH occasions. Thewireless device may select an LBT type in accordance with theindication.

A wireless device may receive one or more messages from a base stationthat semi-statically configure the wireless device to receive one ormore downlink signals (e.g., PDSCH, PDCCH, CSI-RS, or SSB) in one ormore symbols of a slot. The wireless device may receive at least one DCI(e.g., DCI format 1_0, DCI format 1_1, or DCI format 0_1) thatdynamically schedules one or more monitoring occasions in the one ormore symbols of the slot. For example, the wireless device may receiveCSI-RS or PDSCH based on the one or more monitoring occasions. Awireless device may receive one or more messages from the base stationthat semi-statically configure the wireless device to transmit one ormore uplink signals (e.g., SRS, PUSCH, PUCCH, or PRACH) in one or moresymbols of a slot. The wireless device may receive at least one DCI(e.g., DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1,or DCI format 2_3) that dynamically schedules one or more transmissionoccasions in the one or more symbols of the slot. For example, thewireless device may transmit a PUSCH, a PUCCH, a PRACH, or an SRS via atleast one of the one or more transmission occasions. The one or moresymbols of the slot may be inside a COT. The COT may be acquired by thebase station and/or a wireless device. For example, within the COT,there may be one or more DL-UL transmission and/or UL-DL transmissionswitching points. In order to enhance random access transmissionopportunities in unlicensed bands, the base station may dynamicallyschedule one or more PRACH transmission occasions, for example, during aCOT (e.g., in at least one symbol of the slot). For example, the one ormore PRACH transmission occasions may not be overlapped with at leastone PRACH transmission occasion semi-statically configured by a basestation (e.g., via broadcast message(s)). In an existing radio accesstechnology (e.g., 4G and/or 5G), a dynamic assignment of one or morePRACH transmission occasions is not supported. In an unlicensed band, awireless device may transmit and/or receive any message (Msg1 1220, Msg2 1230, Msg 3 1230, and/or contention resolution 1250), for example,when an LBT is successful in the unlicensed band. This may result in along delay for the wireless device to camp on a cell configured in theunlicensed band. For example, a base station may not be able todynamically override a configuration of the symbols in the slot by afirst slot format, e.g., a symbol of the slot configured as a downlinksymbol by RRC or allocated by DCI. Therefore, the base station may notbe able to dynamically schedule PRACH transmission occasions and providewireless devices with dynamic random access opportunities, which mayresult in reduced random access opportunities for the wireless devicesand increased latency in the random access procedures.

The long delay may depend on a result of LTB performed by the wirelessdevice and/or a level of congestion on the unlicensed band. Thus, thereis a need to reduce the long delay occurring in the existing radioaccess technology. Example embodiments in the specification may providea mechanism and/or one or more parameters to enhance the random accessprocedure. Example embodiments improve a likelihood that a random accessprocedure is successfully completed in an unlicensed band. Thereby, alatency and/or battery power consumption may be improved.

A wireless device may be semi-statically or dynamically scheduled toreceive downlink signals or to transmit uplink signals in one or moresymbols of a slot. The one or more symbols of the slot may be inside aCOT. The COT may be acquired by a base station. However, the wirelessdevice may later receive a downlink control signal, e.g., a DCIindicating one or more PRACH transmission occasions. The one or morePRACH transmission occasions may be dynamically scheduled by the basestation in the COT. For example, the downlink control signal (the DCI)may indicate to the wireless device that the one or more PRACHtransmission occasions are allocated inside the COT. For example, thewireless device may determine an LBT type abased on whether the one ormore PRACH transmission occasions are allocated inside the COT and mayperform the LBT type for transmitting a preamble in the one or morePRACH transmission occasions.

In an example, for a given slot, there may be two different formats; afirst slot format for the given slot that is semi-statically configured(e.g., by a RRC signaling configuring a cell-level slot format) and asecond slot format for the given slot that is dynamically configured.The first slot format and the second slot format may be different. Forexample, the one or more PRACH transmission occasions may be in at leastone symbol of the one or more symbols of the slot that weresemi-statically or dynamically scheduled with one or more DL assignmentsor one or more UL grants. However, if the wireless device receives theone or more DL assignments or transmits via the one or more UL grants,the one or more DL/UL transmissions may interfere with one or more PRACHtransmissions by other wireless devices in the one or more PRACHtransmission occasions. There is a need to coordinate a slot format of aslot between two slot formats configured semi-statically anddynamically.

A wireless device may receive one or more RRC messages comprising one ormore parameters that configure a first slot format of at least one slotin a number of slots. The first slot format may indicate one or moresymbols in the at least one slot as a downlink symbol and/or an uplinksymbol and/or a flexible symbol. The wireless device may receive a DCIthat indicates a second slot format of the at least one slot in thenumber of slots. The second slot format may indicate one or more symbolsin the at least one slot as a downlink symbol and/or an uplink symboland/or flexible symbol. The second slot format may indicate one or moresymbols indicated as downlink symbols by the first slot format asdownlink symbols. The second slot format may indicate one or moresymbols indicated as uplink symbols by the first slot format as uplinksymbols. The second slot format may indicate one or more symbolsindicated as flexible symbols by the first slot format as downlinksymbols or uplink symbols or flexible symbols.

The DCI that indicates the second slot format may be transmitted, forexample, in within a COT (e.g., the beginning of a COT) to indicateinformation of the COT structure, for example, length of the COT (suchas number of slots and/or symbols in the COT), end of the COT, ordownlink and uplink switching points in the COT. The DCI may be used toindicate dynamically scheduled uplink and/or downlink symbols to thewireless device. The DCI may be used to indicate dynamically scheduledPRACH resources comprising one or more PRACH transmission occasions tothe wireless device. The one or more PRACH transmission occasions may beallocated from the one or more uplink symbols and/or the one or moreflexible symbols indicated by the first slot format and/or the secondslot format. The DCI may comprise one or more parameters of at least onetime resource and/or at least one frequency resource to indicate the oneor more PRACH transmission occasions, and/or one or more preambleindexes, and/or one or more associations between the one or more PRACHtransmission occasions and the one or more preamble indexes. However,the overhead of receiving and decoding the DCI with increased size mayresult in increased latency and power consumption by the wirelessdevice.

One or more PRACH transmission occasions may be dynamically scheduled inone or more symbols of at least one slot from one or more slots in aCOT. A DCI may indicate a slot format of the one or more symbols of theat least one slot. The one or more symbols may not be previouslyconfigured, or may be configured by RRC as downlink and/or uplink and/orflexible symbols, or may be semi-statically and/or dynamically scheduledfor receiving one or more downlink signals and/or transmitting one ormore uplink signals. In an example, the one or more symbols may only beconfigured as flexible symbols. In an example, the one or more symbolsmay only be configured as uplink symbols. In an example, the one or moresymbols may be configured as one or more flexible and one or more uplinksymbols. The DCI may indicate the one or more symbols as random accesssymbols. The DCI may indicate a timing for the beginning of the randomaccess symbols. The DCI may indicate a number of symbols and/or slotallocated to the random access symbols. The random access symbols maycomprise the one or more PRACH transmission occasions.

In an existing technology, a slot format dynamically configured for aslot may override a slot format semi-statically configured as ‘flexible’for the slot. This overriding priority may be inefficient in anunlicensed band. For example, in an unlicensed band, a dynamicallyconfigured slot format may be efficient to adaptively and/or flexiblychange the slot format, for example, depending on an LBT results,interference level, and/or congestion level int the unlicensed band.Example embodiments provide a efficient mechanism to determine whether aslot format dynamically configured for a slot may override a slot formatsemi-statically configured as ‘flexible’ for the slot or not.

In an example embodiment, as shown in FIG. 20, a wireless device mayreceive one or more messages. The one or more messages may comprisefirst resource configuration parameters of a random access procedure,and/or second configuration parameters of a downlink control signal,and/or third configuration parameters of a slot format. The base stationmay perform an LBT and, if the LBT is successful, the base station mayinitiate a COT by transmitting the downlink control signal. The wirelessdevice may receive the downlink control signal based on the secondconfiguration parameters. The downlink control signal may indicate theCOT structure information. The downlink control signal may indicate oneor more PRACH occasions. The wireless device may determine a PRACHoccasion from the one or more PRACH occasions. The wireless device mayperform a type of LBT (e.g., no LBT (CAT1), or short LBT (CAT2), or LBTCAT4). The wireless device may transmit a preamble via the PRACHoccasion.

As shown in FIG. 21, the wireless device may receive, from a basestation, one or more downlink reference signal comprising a firstdownlink reference signal. The wireless device may receive RRC messagescomprising first resource configuration parameters. The first resourceconfiguration parameters may indicate at least one of: a plurality ofpreamble indexes of a plurality of preambles; one or more time resourcesof one or more random access channel (RACH) occasions (ROs); one or morefrequency resources of the one or more ROs; a first association betweenthe one or more ROs and the one or more downlink reference signals(e.g., SSB or CSI-RS); a second association between the plurality ofpreambles and the one or more reference signals. The wireless device mayselect the first downlink reference signal for a preamble transmission.The wireless device may select a preamble from the plurality ofpreambles in response to the first downlink reference signal selectedfrom the one or more downlink reference signals. A received power of thefirst downlink reference signal may be above a threshold, or the firstdownlink reference signal may be quasi-colocated with a second downlinkreference signal, where the received power of the second downlinkreference signal may be above the threshold.

In an example embodiment as shown in FIG. 21, the wireless device mayreceive RRC messages comprising second resource configuration parametersof a downlink control signal (e.g., a DCI or a DMRS). The downlinkcontrol signal may be a DCI. The second configuration parameters mayindicate a search space set of a downlink control channel (e.g., aPDCCH) indicating the DCI. The second configuration parameters mayindicate a first radio network temporary identifier (RNTI) associatedwith a reception of the DCI (e.g., SFI-RNTI, a pre-defined RNTI, or afixed RNTI). The second configuration parameters may indicate a payloadsize of the DCI. The wireless device may receive the downlink controlsignal based on the second configuration parameters. The downlinkcontrol signal may indicate COT information (e.g., COT length, end ofCOT, DL/UL switching points, format of symbols and slots in the COT,etc.) and/or dynamically schedule PRACH occasions in the COT. The secondconfiguration parameters may indicate one or more slot format indexes ofone or more slot formats. The second configuration parameters mayindicate one or more slot format combination identifiers of one or moreslot format combinations, where each of the one or more slot formatcombinations comprises of at least one slot format index of the one ormore slot format indexes. The downlink control signal may use the one ormore slot formats to indicate COT information and/or the PRACHoccasions.

In an example embodiment as shown in FIG. 21, the wireless device mayreceive RRC messages comprising third configuration parameters of slotformats (e.g., a periodicity and/or a pattern). The third configurationparameters may indicate a first slot format of a first slot of aplurality of slots. The first slot format may indicate one or moresymbols of the first slot as one or more uplink symbols. The first slotformat may indicate the one or more symbols of the first slot as one ormore flexible symbols. The first slot format may indicate the one ormore symbols of the first slot comprising at least one of one or moreuplink symbols and one or more flexible symbols.

The downlink control signal may indicate one or more symbols, of thefirst slot of the plurality of slots, as one or more PRACH occasions.The downlink control signal may indicate a COT structure information.The downlink control signal may comprise an indicator that indicatesdynamic allocation of the one or more PRACH occasions in the COT. Thewireless device may determine the resources (time/frequency/preamble) ofthe one or more PRACH occasions based on the first resourceconfiguration parameters. The downlink control signal may comprise atime offset that indicates a first PRACH occasion from the one or morePRACH occasions in the COT. The time offset may be in seconds, slots,and/or in symbols, with respect to a first symbol of the COT. Thedownlink control signal may comprise one or more symbol indexes of oneor more slots in the COT to indicate the one or more PRACH occasions.The downlink control signal may comprise a second slot format. Thesecond slot format may be configured by the second configurationparameters. The second slot format may indicate the one or more symbolsof the first slot as the one or more random access (PRACH) occasions.

The wireless device may be configured by a first slot format of the oneor more symbols of the first slot in the plurality of slots, where thethird (RRC) configuration parameters may comprise the first slot format.The wireless device may then receive the downlink control signal thatindicates the second slot format of the one or more symbols of the firstslot. The downlink control signal may indicate the second slot formatfor a number of slots in the COT. For example, the wireless device maydetermine a duration of the COT (and/or a remaining duration of the COT)based on a length of the second slot format. The second slot format mayindicate at least one symbol of the one or more symbols as random accesssymbols. The random access symbols may be denoted by an “R”. The one ormore random access symbols may comprise the one or more PRACH occasions.The wireless device may determine the one or more PRACH occasions basedon a priority of the first slot format and the second slot format of theone or more symbols of the first slot.

For example, for one or more symbols indicated as downlink symbols (D)by the first slot format, the wireless device may not expect the secondslot format to indicate the one or more symbols as uplink symbols (U) orflexible symbols (F) or random access symbols (R). For example, for oneor more symbols indicated as uplink symbols (U) by the first slotformat, the wireless device may not expect the second slot format toindicate the one or more symbols as downlink symbols (D) or flexiblesymbols (F). One or more symbols indicated as uplink symbols (U) by thefirst slot format may be indicated as random access symbols (R) by thesecond slot format. One or more symbols indicated as flexible symbols(F) by the first slot format may be indicated as random access symbols(R), uplink symbols (U), downlink symbols (D) by the second slot format.For example, FIG. 22 shows an example where the first slot formatindicates symbols 4-8 as flexible symbols (F), and the second slotformat indicates the same symbols 4-8 as random access symbols (R). Inan example, the second slot format may override (or restrict) the firstslot format's indication for symbols 4-8 with random access symbols (R)to dynamically schedule random access resources. In an example,different overriding (or restricting) rule(s) may be implemented. Forexample, if one or more symbols indicated as downlink symbols (D) by thefirst slot format may be indicated as random access symbols (R) by thesecond slot format, the second slot format may override (or restrict)the first slot format. For example, if one or more symbols indicated asuplink symbols (U) by the first slot format may be indicated as randomaccess symbols (R) by the second slot format, the second slot format mayoverride (or restrict) the first slot format.

FIG. 23 shows an example where the base station performs an LBT andacquires a COT. The base station may transmit a DCI in first downlinkresources of the COT. The DCI may comprise a slot format indicator thatindicates to one or more wireless devices a slot format of one or moresymbols of one or more slots in the COT. The slot format may indicatethe COT structure, e.g., a direction of each symbol of the one or moresymbols in the COT, the COT length, a number of slots and/or symbols inthe COT, an end of the COT, etc. The slot format may further indicateone or more symbols in the COT as one or more random access symbols (R).The one or more random access symbols may comprise one or more PRACHoccasions for one or more random access preamble transmissions.

In an example embodiment, as shown in FIG. 24, a wireless device mayreceive one or more RRC messages from a base station. The one or moreRRC messages may comprise first configuration parameters indicating atleast one downlink resource for monitoring and receiving a downlinkcontrol signal (e.g., a DCI). The at least one downlink resource maycomprise one or more time resources and/or one or more frequencyresources of a search space set. The first configuration parameters mayfurther indicate a radio network identifier (e.g., an RNTI) of thedownlink control signal. The one or more RRC messages may comprisesecond configuration parameters of slot formats (e.g., a periodicityand/or a pattern). The second configuration parameters may indicate afirst slot format of a first slot of a plurality of slots. The firstslot format may indicate one or more symbols of the first slot as one ormore downlink symbols. The second configuration parameters may indicatethe one or more symbols of the first slot to be scheduled for monitoringa downlink channel (e.g., a PDCCH, a PDSCH, a CSI-RS, or a PBCH). Thewireless device may receive the downlink control signal via the at leastone downlink resource. The downlink control signal may dynamicallyschedule random access resources (PRACH occasions) in the first slot.The downlink control signal may indicate that at least one symbol of theone or more symbols of the first slot is allocated as one or more randomaccess preamble transmission occasions. In response to receiving thedownlink control signal, the wireless device may cancel monitoring ofthe downlink channel during the at least one symbol or the one or moresymbols.

In an example embodiment, a wireless device may receive one or more RRCmessages from a base station. The one or more RRC messages may comprisefirst configuration parameters of one or more downlink control signals.The first configuration parameters may indicate at least one downlinkresource for monitoring and receiving the one or more downlink controlsignals (e.g., DCIs). The at least one downlink resource may compriseone or more time resources and/or one or more frequency resources of oneor more search space sets. The first configuration parameters mayfurther indicate one or more radio network temporary identifiers (e.g.,RNTIs) of the at least one downlink control signal. The one or more RRCmessages may comprise second configuration parameters of slot formats(e.g., a periodicity and/or a pattern). The second configurationparameters may indicate a first slot format of a first slot of aplurality of slots. The first slot format may indicate one or moresymbols of the first slot as one or more downlink symbols. The wirelessdevice may receive via the at least one downlink resource, a firstdownlink control signal (e.g., a DCI format 1_0, a DCI format 1_1, or aDCI format 0_1) from the one or more downlink control signals. The firstdownlink control signal may dynamically schedule downlink assignmentsfor the wireless device. For example, the first downlink control signalmay indicate the one or more symbols of the first slot to be scheduledfor monitoring a downlink channel (e.g., a PDCCH, a PDSCH, or a CSI-RS).The wireless device may receive, via the at least one downlink resource,a second downlink control signal from the one or more downlink controlsignals. The second downlink control signal may dynamically schedulerandom access resources (PRACH occasions) in the first slot. Thedownlink control signal may indicate that at least one symbol of the oneor more symbols of the first slot is allocated as one or more randomaccess preamble transmission occasions. In response to receiving thesecond downlink control signal, the wireless device may cancelmonitoring of the downlink channel during the at least one symbol or theone or more symbols.

In an example embodiment, as shown in FIG. 25, a wireless device mayreceive one or more RRC messages from a base station. The one or moreRRC messages may comprise first configuration parameters indicating atleast one downlink resource for monitoring and receiving a downlinkcontrol signal (e.g., a DCI). The at least one downlink resource maycomprise one or more time resources and/or one or more frequencyresources of a search space set. The first configuration parameters mayfurther indicate a radio network identifier (e.g., an RNTI) of thedownlink control signal. The one or more RRC messages may comprisesecond configuration parameters of slot formats (e.g., a periodicity,and/or a pattern). The second configuration parameters may indicate afirst slot format of a first slot of a plurality of slots. The firstslot format may indicate one or more symbols of the first slot as one ormore uplink symbols. The second configuration parameters may indicatethe one or more symbols of the first slot to be scheduled fortransmitting one or more uplink transmissions (PUCCH or PUSCH), e.g.,one or more transport blocks, an uplink control information (UCI),and/or a sounding reference signal (SRS). The wireless device mayreceive the downlink control signal via the at least one downlinkresource. The downlink control signal may dynamically schedule randomaccess resources (PRACH occasions) in the first slot. The downlinkcontrol signal may indicate that at least one symbol of the one or moresymbols of the first slot is allocated as one or more random accesspreamble transmission occasions. In response to receiving the downlinkcontrol signal, the wireless device may cancel transmitting the one ormore uplink transmissions via the at least one symbol or the one or moresymbols.

In an example embodiment, a wireless device may receive one or more RRCmessages from a base station. The one or more RRC messages may comprisefirst configuration parameters of one or more downlink control signals.The first configuration parameters may indicate at least one downlinkresource for monitoring and receiving the one or more downlink controlsignals (e.g., a DCIs). The at least one downlink resource may compriseone or more time resources and/or one or more frequency resources of oneor more search space sets. The First configuration parameters mayfurther indicate one or more radio network identifiers (e.g., RNTIs) ofthe at least one downlink control signals. The one or more RRC messagesmay comprise second configuration parameters of slot formats (e.g., aperiodicity, and/or a pattern). The second configuration parameters mayindicate a first slot format of a first slot of a plurality of slots.The first slot format may indicate one or more symbols of the first slotas one or more uplink symbols. The wireless device may receive via theat least one downlink resource, a first downlink control signal (e.g., aDCI format 0_0, a DCI format 0_1, a DCI format 1_0, a DCI format 1_1, ora DCI format 2_3) from the one or more downlink control signals. Thefirst downlink control signal may dynamically schedule uplink grants forthe wireless device. For example, the first downlink control signal mayindicate the one or more symbols of the first slot to be scheduled fortransmitting one or more uplink transmissions (PUCCH or PUSCH), e.g.,one or more transport blocks, an uplink control information (UCI),and/or a sounding reference signal (SRS). The wireless device mayreceive via the at least one downlink resource, a second downlinkcontrol signal from the one or more downlink control signals. The seconddownlink control signal may dynamically schedule random access resources(PRACH occasions) in the first slot. The downlink control signal mayindicate that at least one symbol of the one or more symbols of thefirst slot is allocated as one or more random access preambletransmission occasions. In response to receiving the second downlinkcontrol signal, the wireless device may cancel transmitting the one ormore uplink transmissions via the at least one symbol or the one or moresymbols.

FIG. 26 is a flow diagram of an example embodiment for a wireless devicescheduled with dynamic PRACH using slot formats as per an aspect of thepresent disclosure. As shown in FIG. 26, a wireless device may receive aradio resource control (RRC) message comprising one or moreconfiguration parameters for a random access channel (RACH). Thewireless device may further receive a downlink control information (DCI)comprising a field indicating a slot format indication (SFI), for aslot, among a plurality of SFIs, wherein the plurality of SFIs indicateuplink, flexible, and random access symbols. The wireless device maydetermine radio resources of one or more RACH occasions (ROs) of theslot based on the one or more configuration parameters and/or at leastone random access symbol indicated by the SFI for the slot. The wirelessdevice may transmit a preamble via the radio resources of the one ormore ROs.

According to various embodiments, the one or more configurationparameters may indicate one or more second ROs, wherein the one or moresecond ROs may be semi-statically repeated based on a period. The one ormore configuration parameters may indicate a plurality of preambleindexes of a plurality of preambles. The one or more configurationparameters may indicate first time domain resources of the one or moreROs. The first time domain resources of the one or more ROs may comprisea first number of time domain ROs per slot and/or a second number ofsymbols for a duration of each of the time-domain ROs. The one or moreconfiguration parameters may indicate one or more frequency domainresources of the one or more ROs. The one or more frequency domainresources of the one or more ROs may indicate a frequency offset of afirst RO of the one or more ROs with respect to a first resource blockand/or a third number of ROs multiplexed in frequency domain per timeinstance. The wireless device may determine the radio resources of theone or more ROs by determining the slot as a physical RACH (PRACH) slotin response to the SFI indicating the at least one random access symbolin the slot and/or mapping the first time domain resources of the one ormore ROs to the slot, and the one or more frequency resources of the oneor more ROs to one or more resource blocks. The wireless device maydetermine a first symbol, of a plurality of symbols comprising the atleast one random access symbol of the slot, as a starting symbol for themapping the first time domain resources in the slot. The one or more ROsmay be mapped consecutively from the starting symbol. The one or moreROs may be mapped to at least one uplink symbol or flexible symbolindicated by the SFI for the slot. The one or more ROs may be mapped tothe at least one random access symbol indicated by the SFI for the slot.

FIG. 27 is a flow diagram of an example embodiment for a base stationdynamically scheduling PRACH using slot formats as per an aspect of thepresent disclosure. As shown in FIG. 27, the base station may transmit aradio resource control (RRC) message comprising one or moreconfiguration parameters for a random access channel (RACH). The basestation may further transmit a downlink control information (DCI)comprising a field indicating a slot format indication (SFI), for aslot, among a plurality of SFIs, wherein the plurality of SFIs indicateuplink, flexible, and random access symbols. The base station mayreceive a preamble via radio resources of one or more ROs of the slot,wherein the radio resources are determined based on the one or moreconfiguration parameters and/or at least one random access symbolindicated by the SFI for the slot.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). A base station may comprise multiple sectors. When thisdisclosure refers to a base station communicating with a plurality ofwireless devices, this disclosure may refer to a subset of the totalwireless devices in a coverage area. This disclosure may refer to, forexample, a plurality of wireless devices of a given LTE or 5G releasewith a given capability and in a given sector of the base station. Theplurality of wireless devices in this disclosure may refer to a selectedplurality of wireless devices, and/or a subset of total wireless devicesin a coverage area which perform according to disclosed methods, and/orthe like. There may be a plurality of base stations or a plurality ofwireless devices in a coverage area that may not comply with thedisclosed methods, for example, because those wireless devices or basestations perform based on older releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed to one or more of the various embodiments.

If A and B are sets and every element of A is also an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayalso refer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state

In this disclosure, various embodiments are disclosed. Limitations,features, and/or elements from the disclosed example embodiments may becombined to create further embodiments within the scope of thedisclosure.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Furthermore, many features presented above are described as beingoptional through the use of “may” or the use of parentheses. For thesake of brevity and legibility, the present disclosure does notexplicitly recite each and every permutation that may be obtained bychoosing from the set of optional features. However, the presentdisclosure is to be interpreted as explicitly disclosing all suchpermutations. For example, a system described as having three optionalfeatures may be embodied in seven different ways, namely with just oneof the three possible features, with any two of the three possiblefeatures or with all three of the three possible features.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (i.e.hardware with a biological element) or a combination thereof, all ofwhich may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.Additionally, it may be possible to implement modules using physicalhardware that incorporates discrete or programmable analog, digitaland/or quantum hardware. Examples of programmable hardware comprise:computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); andcomplex programmable logic devices (CPLDs). Computers, microcontrollersand microprocessors are programmed using languages such as assembly, C,C++ or the like. FPGAs, ASICs and CPLDs are often programmed usinghardware description languages (HDL) such as VHSIC hardware descriptionlanguage (VHDL) or Verilog that configure connections between internalhardware modules with lesser functionality on a programmable device. Theabove mentioned technologies are often used in combination to achievethe result of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the scope. In fact, after reading the abovedescription, it will be apparent to one skilled in the relevant art(s)how to implement alternative embodiments. Thus, the present embodimentsshould not be limited by any of the above described exemplaryembodiments.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the actions listed in any flowchart may bere-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112. Claims that do not expressly include the phrase “means for”or “step for” are not to be interpreted under 35 U.S.C. 112.

What is claimed is:
 1. A method comprising: receiving, by a wirelessdevice, a radio resource control (RRC) message comprising one or moreconfiguration parameters for a random access channel (RACH); receiving adownlink control information (DCI) comprising a field indicating a slotformat indication (SFI), for a slot, among a plurality of SFIs, whereinthe plurality of SFIs indicate uplink, flexible, and random accesssymbols; determining radio resources of one or more RACH occasions (ROs)of the slot based on: the one or more configuration parameters; and atleast one random access symbol indicated by the SFI for the slot; andtransmitting a preamble via the radio resources of the one or more ROs.2. The method of claim 1, wherein: the one or more configurationparameters indicate one or more second ROs; and the one or more secondROs are semi-statically repeated based on a period.
 3. The method ofclaim 1, wherein the one or more configuration parameters indicate atleast one of the following for the one or more ROs: a plurality ofpreamble indexes of a plurality of preambles; first time domainresources of the one or more ROs; or one or more frequency domainresources of the one or more ROs.
 4. The method of claim 3, wherein thefirst time domain resources of the one or more ROs comprise: a number oftime domain ROs per slot; and a number of symbols for a duration of eachof the time-domain ROs.
 5. The method of claim 3, wherein the one ormore frequency domain resources of the one or more ROs indicate: afrequency offset of a first RO of the one or more ROs with respect to afirst resource block; and a number of ROs multiplexed in frequencydomain per time instance.
 6. The method of claim 3, wherein determiningthe radio resources of the one or more ROs comprises: determining theslot as a physical RACH (PRACH) slot in response to the SFI indicatingthe at least one random access symbol in the slot; and mapping the firsttime domain resources of the one or more ROs to the slot, and the one ormore frequency resources of the one or more ROs to one or more resourceblocks.
 7. The method of claim 6, wherein the wireless device determinesa first symbol, of a plurality of symbols comprising the at least onerandom access symbol of the slot, as a starting symbol for the mappingthe first time domain resources in the slot.
 8. The method of claim 7,wherein the one or more ROs are mapped consecutively from the startingsymbol.
 9. The method of claim 8, wherein the one or more ROs are mappedto at least one uplink symbol or flexible symbol indicated by the SFIfor the slot.
 10. The method of claim 7, wherein the one or more ROs aremapped to the at least one random access symbol indicated by the SFI forthe slot.
 11. A wireless device comprising: one or more processors; andmemory storing instructions that, when executed by the one or moreprocessors, cause the wireless device to: receive, from a base station,a radio resource control (RRC) message comprising one or moreconfiguration parameters for a random access channel (RACH); receive adownlink control information (DCI) comprising a field indicating a slotformat indication (SFI), for a slot, among a plurality of SFIs, whereinthe plurality of SFIs indicate uplink, flexible, and random accesssymbols; determine radio resources of one or more RACH occasions (ROs)of the slot based on: the one or more configuration parameters; and atleast one random access symbol indicated by the SFI for the slot; andtransmit a preamble via the radio resources of the one or more ROs. 12.The wireless device of claim 11, wherein: the one or more configurationparameters indicate one or more second ROs; and the one or more secondROs are semi-statically repeated based on a period.
 13. The wirelessdevice of claim 11, wherein the one or more configuration parametersindicate at least one of the following for the one or more ROs: aplurality of preamble indexes of a plurality of preambles; first timedomain resources of the one or more ROs; or one or more frequency domainresources of the one or more ROs.
 14. The wireless device of claim 13,wherein the first time domain resources of the one or more ROs comprise:a number of time domain ROs per slot; and a number of symbols for aduration of each of the time-domain ROs; and the one or more frequencydomain resources of the one or more ROs indicate: a frequency offset ofa first RO of the one or more ROs with respect to a first resourceblock; and a number of ROs multiplexed in frequency domain per timeinstance.
 15. The wireless device of claim 13, wherein the instructionsthat cause the wireless device to determine the radio resources of theone or more ROs further cause the wireless device to: determine the slotas a physical RACH (PRACH) slot in response to the SFI indicating the atleast one random access symbol in the slot; and map the first timedomain resources of the one or more ROs to the slot, and the one or morefrequency resources of the one or more ROs to one or more resourceblocks.
 16. The wireless device of claim 15, wherein the instructionsthat cause the wireless device to map the first time domain resources ofthe one or more ROs to the slot further cause the wireless device todetermine a first symbol, of a plurality of symbols comprising the atleast one random access symbol of the slot, as a starting symbol formapping the first time domain resources in the slot.
 17. The wirelessdevice of claim 16, wherein the one or more ROs are mapped consecutivelyfrom the starting symbol.
 18. The wireless device of claim 17, whereinthe one or more ROs are mapped to at least one uplink symbol or flexiblesymbol indicated by the SFI for the slot.
 19. The wireless device ofclaim 18, wherein the one or more ROs are mapped to the at least onerandom access symbol indicated by the SFI for the slot.
 20. A systemcomprising: a base station comprising: one or more first processors; anda first memory storing instructions that, when executed by the one ormore first processors of the base station, cause the base station to:transmit a radio resource control (RRC) message comprising one or moreconfiguration parameters for a random access channel (RACH); transmit adownlink control information (DCI) comprising a field indicating a slotformat indication (SFI), for a slot, among a plurality of SFIs, whereinthe plurality of SFIs indicate uplink, flexible, and random accesssymbols; and receive a preamble via radio resources of one or more RACHoccasions (ROs) of the slot; and a wireless device comprising: one ormore second processors; and a second memory storing instructions that,when executed by the one or more second processors, cause the wirelessdevice to: receive the RRC message; receive the DCI; determine the radioresources of the one or more ROs based on: the one or more configurationparameters; and at least one random access symbol indicated by the SFIfor the slot; and transmit the preamble via the radio resources of theone or more ROs.